Screen Printing Fundamentals

1. Intro: Hi, I'm Eric, and welcome to the wonderful world of screen printing. Did you know that screen printing or silkscreen is the most versatile printing process ever invented? The widest variety of materials is printed using a screen than any other method, even digital. Screen printing is a stencil process that is adaptable to many different surfaces and inks. I first got into screen printing when I wanted to make t-shirts for my band in high school. I majored in printmaking in college, and then started my own clothing line and print shop. Soon after, I got into more specialized printing and I now primarily work for advertising agencies and artists. I make props for movies and commercials and artists' canvases. I've printed [inaudible] to marshmallows, materials for Janelle Monet's record release party, and everything in between. I love to print on materials that I have not printed on before. Screen printing is a very process-based medium, meaning that there's a lot of steps involved. In this class, we will explore each of them to better understand how they relate to getting a great final print. We're going to learn some simple stencil techniques and some more complicated stencil techniques. We're also going to learn a couple different methods to register. This class is for a beginner and intermediate printmakers alike. For those just starting out, I will guide you through every step of the process, and for those with a little bit of experience, I will expand and build upon your knowledge. The materials needed for this class will be a screen, squeegee, hinge clamps, and water-based ink. There are many varieties for each of these, but whatever you have will work. In this class, you will gain a solid foundation for screen printing. By learning several different ways to do each step, you'll be able to apply these skills to print other wide variety of materials. The class project will be to print on something that you find around the house. It should be flat, smooth, and made out of a natural material like paper, wood, or cotton. Let's get creative and learn how to make some prints. [MUSIC] 2. Intro to Project: The class project will be to print on something that you find around the house. I think everyone has something lying around that they can dress up with some screen printing. It should be a natural material that is flat and smooth, so something like paper, wood, or cotton. Some examples might include a cloth napkin, a piece of paper, a paper bag, a book cover, a small piece of wood, or an old map. I want you to find an interesting material to print on to show up the versatility of screen printing. For a successful first project, I would recommend sticking to something around 8 by 10 inches and not making the line quality too complicated. It's easier to get a handle on the process with a smaller, simpler image and move up from there. There are many different ways to approach screen printing and many different techniques. In this class, I will show you several different ways to make, print, and register the screen. This class is designed to be as much of a how-to as it is a resource for you to come back to in the future as you grow with screen printing. Watch each section in its entirety before you advance. Watch through the different options of making a screen before you pick one, then find a material to print on. See you in the next lesson. 3. History: I want to give you a very brief history of screen printing and why the process was invented. Screen printing is a technique that allows ink to pass through a stencil that is affixed to a screen. The earliest examples come from China and Japan, around 1000 AD. Screen printing solved two major problems at the time with traditional printing processes, the ability to print opaque white ink and to print these stencil without having to tie it together. What I mean by that can be seen in this example of a stencil for the letter O. In order for it to be printed with traditional stencil methods, it needs to be tied together like this. Here are some Japanese paper stencils that are attached with thin metal wires to hold it in place while being printed. By attaching the stencil to a silk mesh, it made it possible to print more complicated designs without the wires. Screen printing first came into a prominent role in the industrial decorating of the early 20th century, so things like wallpaper or fabric that had to be mass-produced with a stencil or a paintbrush. The rise of the silk industry in New Jersey provided advancements in silk production and produced higher quality and more consistent material to affix the stencils on. The term silkscreen was born. Nowadays, screens are not made out of silk, they're made out of polyester. But I still think that's silkscreen has a nice ring to it. Pennants were a popular souvenir item at the time. These were primarily made with cut felt and traditional stencil methods and hand painting. Incorporating screen printing into the process made it able to print directly on the felt pennant with opaque white paint and work much faster and more consistently. It was not possible to do this with traditional printing methods like intaglio, etching, woodcut, and lithography. These advancements took screen printing from a purely artistic medium into hundreds of different industries and applications. 4. Materials: Now let's go over the materials you will need for this class. Because of the way this lesson is structured, you might not need all of these materials, so please watch the videos all the way through the screen making section. With that being said, let's look at the options. Starting with a screen, a squeegee, water-based ink, hinge clamps, tape, a mixing stick, a spray bottle filled with water, a rag, preferably an old t-shirt or some cotton cloth, not paper towels, test paper, this can be newsprint or cardboard, anything you got, retarder base for acrylic screen printing ink, a knife, X-Acto blade or scissors, some Some material like a thin piece of cardboard, a piece of paper, but make sure that you can cut through it easily, screen drawing fluid and screen filler, and a paintbrush. If using the photo emulsion method, you will need a scoop coater, dual-cure or Diazo-based photo emulsion, a light source, either a halogen bulb or an LED, clear film, paint markers or India ink, emulsion reclaimer, gloves, and a scrub brush. In addition, you will need a flat surface to print on and an area to wash out your screens. This can be a slop sink or a shower or even the hose outside. I use this slop sink and a power washer. I use this coated particle board called melamine, but you could use plywood or anything sturdy and flat. I like the hard coating because it's easy to clean. Next, let's talk about the screen. 5. Screens and Mesh: Let's talk about the most important part of screen printing, the screen. A screen is composed of the actual frame and the mesh that is attached to it. There are three types of screen printing frames; wood, aluminum, and retention bubble. Wood is the cheapest in terms of cost and quality. A wood frame is good for printers just starting out and readily available and most art stores, the meshes attached using staples. The weaknesses of a wood frame or that it can warp and that the tension in the mesh will get lower over time. Wood has its uses though and for simple one-color projects, it will be sufficient. You can also restretch a wood frame by yourself if you need to. Aluminum is a major step up from a wood frame. Not much more expensive and is the way most screens are made. Now, the mesh is glued in place and keeps us tension longer than wood. The frame will not warp and the mesh can last for years if properly cared for. The edges of the frame are welded and keep water out, letting it dry faster. Retention bubble is the highest quality frame you can buy. They're used by professional print shops so that they have the greatest control over the mesh. The mesh is stretched by the user and can be replaced if it ever gets damaged. On this frame, the meshes inserted into a slot and then tightened. Let's talk about the Mesh. Mesh comes in different sizes that correspond to a number. The lower the number, the bigger and further apart the holes in the mesh are. The higher the number, the tighter together and smaller the holes in the mesh are. You can think of mesh like a screen door. These holes are what allows the ink to pass through the stencil. The mesh is also a factor in how much ink gets deposited onto the surface. If you were printing something like fabric where the ink gets soaked up, you will need bigger holes and a lower number mesh. The opposite is true for something like coated paper stock. Mesh can also be thought of like the resolution on a computer screen. If the holes in the mesh are too large, you'll lose definition and the edges of what you're printing on if it's too complicated, most print shops use a variety of meshes for different projects. Here's a chart of some common sizes and their applications. For this class, I would recommend something between a 110 and a 195 mesh that will cover most of your bases. The higher the mesh count, the harder it is to print the ink through the mesh. The holes are smaller, so they require more skill to print them cleanly. Tension is what allows the ink to pass through the mesh onto what you're printing on. The higher the tension, the easier it is to print, and the more consistent the ink layer is, to push that ink through the mesh on a tight screen is going to be very easy. If you have a lower tension to screen, the mesh can actually become wavy and that will make it harder to print as you pull the squeegee across and it can make the image blurry. If you already have a screen, that's fine and it will work for this class. But if you want to buy something, I would recommend a screen that's between 18 by 20 inches and 20 by 24 inches. The square tubing for the frame is an inch and a half diameter. You can't print right up to the edge of the frame. You want to leave at least two inches between your image and the frame. With a size 20 by 24 outside dimension frame, you're really left with about a 13 by 17 maximum image area. You can always print smaller images on a larger frame or put a couple of different images on the same screen. It's good to have room around your image while printing, and it makes the whole process cleaner and smoother. 6. Squeegees: The squeegee is what you're going to use to push the ink through the stencil and the mesh. Squeegees come in many different sizes from this big guy here, this little itty-bitty one. The handles are either wood or metal. This one's cool, it stands up on the table. The blade is made of urethane and has some flex to it. Durometer is the measure of how soft or hard the urethane is. These correspond to a number, the lower the number, the softer the blade, 60 is soft, 70 is medium, 80 is hard. Soft is going to put down more ink than a harder squeegee. You might want this when you're printing on fabric which requires a little more ink to soak in. The opposite is true when you're printing on paper and you just want a little bit of ink to go down so you want a harder squeegee. When you print, you use the edge of the blade and the right angle it makes. You don't want to bend the blades so much that you are printing with the side of it. When the blade gets dull, I like to sharpen the edge with a piece of sandpaper. The squeegee blade should be about two inches bigger than design you are printing, so about an inch on each side. For this class I would recommend a medium durometer. It's a good all-around squeegee and will work for most projects. 7. Water-based Ink: In this class we'll be using water-based acrylic screen printing ink. You can find many different brands of this at art stores and online. The other thing that we're going to need is some retarder additive. This is going to go with our water-based screen printing ink to help slow down the drying time in your screen and make it much easier to print. There are many different brands of water-based ink. Some are made specifically for printing t-shirts or paper. They make specialized things for almost every surface, but many of them are solvent or plastic-based and requires special chemicals. We will focus on water-based inks for this class. This type of ink is easy to use because it cleans up with water and is readily available. Check your label to see what materials the ink will print on. Usually it's going to be paper, wood, or a natural textile. You can usually print with any water-based acrylic ink found in art stores, even if it is not specifically for screen printing. You always want to do is sample before you print on a new material to make sure that the ink will stick. Some inks are thick and some are thin. If an ink is too thick, you can add water to make it more viscous. I like to mix in a fresh container. I start by adding a little more ink than I think I will need for my print run. Next I add my retarder base about 3-5 percent. Read the label. Then add ink with water to the desired consistency. The more water you add, the more retarder you will need because the ink evaporates faster. In addition to retarder base, ink manufacturers sell transparent base and printing base. Printing base can be used to extend an ink color and make more of it. Transparent base can be added to affect the opacity of the ink. 8. Intro to Screen Making: Now we're going to learn how to get our image onto our screen and make our stencil. We're going to go over a few different ways to do this: two with photo emulsion and two without photo emulsion. It's always good to know a few different techniques for different situations and approaches to projects. Making stencils without photo emulsion is the simplest and most direct way to get your image onto the screen. But there are limitations to the image quality. Making stencils with photo emulsion requires more investment in materials upfront, but gives you the greatest flexibility in the image quality. Please watch all the methods before choosing which one is right for you. 9. Paper Stencil Method : The first technique we're going to go over is the paper stencil method. It's the simplest and fastest technique for getting an image on your screen. There are limitations to this process though. You can only get as complicated with your line work as you can cut out with an X-acto knife or scissors. You can't save your paper stencil after printing. It's a onetime use thing that after you're done making your prints, you throw it away. But it's a good fast way to get started with screen printing and get used to the overall process. You will need your screen, a piece of paper, a blade, spray adhesive, and tape. For this method, we're just going to use a piece of regular old computer paper, something that's nice and thin that we can cut through with an X-acto or scissors. First thing we're going to do is flip our screen around. You can see this one has tape only on the two corners. I remove these so you can see the staples. We're going to measure out our piece of paper. We want to leave a little space around of mesh. We're going to take that off later. This one I'm going to make just a little bit smaller. Something like this. That should be good. We have a little space around our image. Then we're going to draw our image out on the paper. I'm going to do something pretty simple. Just to show you this example, you'll make a little starburst. You can see how this method could be a little time consuming depending on how complicated your image is. Well, for something simple, this is the fastest way to make a screen. There is our stencil. The image is going to go on the back of the screen. When you're printing, it's going to look like this. Whatever you cut out, you have to make sure that it's right reading when the screen looks like this. The next step is attaching our paper stencil to our screen. Now, you could just put the paper stencil down, put your screen down, put your ink in and print it and the ink will actually stick the paper stencil to the screen. But this method just secures it a little better and holds it in place. We're going to put our glue on the front of the stencil. If these were words, it would be reading right now. We're going to apply our spray adhesive to the front of the stencil and then stick it onto the screen. I'm using repositionable Elmer's spray adhesive. Do not use permanent because it will not come off the screen. I'm going to hold it about 18 inches to two feet above the stencil and I'm going to spray a mist and let it rain down onto there. The idea is to put as little adhesive that you need to stick the stencil onto the screen down. I'm going to flip my screen over to the backside. Then I'm going to lay the stencil down on top of it and get it centered. I'm just going to go in here and smooth it out with my hand, get all the ripples out. I'm going to flip our screen back over and we're going to use some tape to cover the areas that don't have stencil around them. I like to use just some cheap tape from a dollar store, nothing too permanent. Again, we want it to just be able to come off the screen very easily after we're done printing. I'm going to tape up all four corners and make sure I don't get too close to the design. We wanted this to be pretty smooth so that when we run our squeegee across, there's no interference. Now we're ready to print this screen. But before we do, we're going to learn a few more stencil techniques. 10. Screen Drawing Method: This technique is great for people that want to get a painterly line in their artwork. Once the image is on the screen, it's reusable and you can save it again and again if you're careful when you clean it. We're going to use our screen drawing fluid and our screen filler, a scoop coater, and a paintbrush. With this method, I'm using a 20 by 24 aluminum screen and a 123 mesh and we're going to use a paintbrush and paint directly onto the screen with our screen drawing fluid. Every time we put down the line, that's what's going to print. You could work from a sketch and trace it onto the screen with a pencil or you could just draw it directly onto the screen. You want to draw it nice and light so that it will come out. Since this is a positive method, meaning whatever we draw is going to print, we want to work on our screen in this orientation so that when we paint down here, it's going to look exactly like that when we actually print our image. When you paint, you want to lift up the corners of the screen, I'm just going to use these rolls of tape to get the screen up off the surface so that when we paint on it, it doesn't dry onto the table. Now if you wanted to, you could place a drawing underneath the screen and trace directly from that. I'm just going to freestyle this a little bit, make this little tree. You don't need to put it on too thick, you don't want it to pull underneath the screen when you're painting it on. Sometimes you may paint it on a little too thick in areas and you can just go from the backside of the screen and smooth it out a little bit. Now that our image is painted onto our screen, we're going to let it air dry. I don't usually like to put a fan on it because it can blow dirt and dust particles into the little sticky blue paint and make it hard to print. Next, we're going to coat our screen with our screen filler, this will block out our stencil. You're going to use your scoop coater for this. Make sure it's two inches smaller than the inside dimension of the frame. You could also use a card or a squeegee for this, but a coater makes a smoother surface and it's way less messy. Our screen filler is dry and we're ready for the next step. Some people like to put this against a wall and do it with two hands or doing on top of a table. I like to work on the floor and either put it up against the corner of a desk and just run the coater up like this or I like to stand up like this, hold the screen at an angle with one hand and then hold the scoop coater so I can control it as I go up. Once our scoop coater is full of screen filler, we're going to put it against the screen, we're going to tilt it forward. You want to make sure that the edge of your coater is nice and tight against the edge of the screen. We're going to bring our angle up so that's touching the screen. See how there's this little point on here. Then we bring it up, a nice steady, we don't want to stop, we don't want to do little skips like this, we just want to touch it, tilt it, slide it up, stop two inches before the top and scrape up the coater. We're just going to do one coat on the front of the screen. The first thing we're going to do is we're going to open our screen filler and we're going to give it a little stir. Some scoop coaters have around edge and a sharp edge. I like to use the round edge if you want it to be pretty thick. We're going to use our round edge, we're going to make sure that that's nice and clean, no dings on here and it's not sharp. If there are, we can use some sandpaper to get those out. We're going to fill this about a quarter of the way up. We're going to touch it, we're going to tilt it, run up nice and slow and even, so we get a nice coat here. Stop about two inches before the top of the frame, tilt the coater back and let the filler settle. Bring it up and give it a final scrape. Then we're going to let this dry in the horizontal position up on top of our tape rolls, just like we did before when we were painting the stencils on. Once our screen is dry, we're going to bring it over to our washout area and then we're going to rinse it out with cold water on both sides and what's going to happen is everywhere where you painted blue is going to start to wash away. Everywhere where it's red is going to stay there making our stencil. We're going to use cold water on both sides of the screen. I'm just using the hose attachment. Now you'll start to see your image appear better on the screen. You can see it comes off quite nicely. Now we're going to dry this in a horizontal position, and we're ready to print. 11. Intro to Photo Emulsion: In this section, we're going to cover the photographic stencil process. Today, most screens are made this way. Artwork arrives to my print shop from an e-mail and we print it out on a computer and make our positive from that. This technique requires understanding of a few different variables and how they relate to each other to achieve the desired result. We're basically shining a light onto a screen that has been sensitized with a photographic emulsion. Let's go over the important points. I'm going to show you two different ways to do this. 12. Emulsion / Coating your screen: To coat our screen we will need, dual cure emulsion, a scoop coater, a ink stirrer, and a cleaning card. The first step in the process is coating the screen. These are two types of emulsion made by the company, Ulano. This one is called LX660 and is a water resistant emulsion. This one is called trifecta and is resistant to water-based inks as well as plastisol and discharge inks. For this class, we want to use something that is water resistant. That's going to be called a dual cure or two-part emulsion, and it's usually going to be diasol photo-based. Check the label. Emulsion comes in many different colors so that you can see the stencil. This one is purple. If it's a two-part emulsion, you'll need to mix the sensitizer into the emulsion in order for it to become light-sensitive. The emulsion is ready to use now. It's light-sensitive, but it's not so light-sensitive that we can't coat it under normal room lights. But you want to avoid sunlight. Sunlight will expose your screen. You can coat in the room light, but you want to let it dry in the dark. The next thing we need is a scoop coater. There are many different kinds of these, but they're generally the same basic idea. Most commonly they look like this, somewhat like this. Some have a cover on top so that protects the edge. This is going to be the most important part of the scoop coater, because this is what comes in contact with the screen. If there's a little dent in here or if it's dirty, it could actually rip your screen or it will leave a streak or a line on the emulsion. The goal here is to lay down a smooth consistent coating of emulsion to make our stencil. Most scoop coaters have a round edge and a sharp edge. I like to use the round edge for most projects. You would want to use the sharp edge if you were making a stencil on a high mesh screen, so about a 200 or above, and you wanted lots of fine detail. When you make a thin stencil, you're going to get a thin coating of ink. When you make a thicker pencil, you're going to get a thicker coating of ink. Every time we use our emulsion, we're going to want to open up the lid and give it a quick stir before we put it in the coater. Sometimes you'll see it'll look a few different colors and you just want to make it look consistent. We're going to fill our scoop coater about halfway up with emulsion. I just want a nice even line in there. If you get an uneven, don't worry, just let it settle a little bit and then it'll work itself out. Most important part, try not to make a mess when you're done pouring. For this, I have a little trick. I like to save the box that the emulsion comes in, and as soon as I'm done pouring it, I put it right back in here. As you can see, this one is a mess and then I don't have to wipe it off all the time. We have our screen ready to go, and we have our scoop coater. I have a piece of cardboard down in case I get anything on the floor. When we coat our screen, we're always going to coat this side first, the back of the screen, what is going to sit against the actual object you're printing on. We're going to coat the front of the screen second. By coating the screen on this side first, we're going to push the emulsion to this side. When we flip it around, we're going to push the emulsion that we already coded and new emulsion that we're putting on to this side. When we drive the screen in the horizontal position, we want this stencil to be thicker on the bottom side of this screen. How thick the emulsion is is going to control how thick the ink deposit is on the print. You want to do one coating on each side so that the mesh becomes encapsulated in this stencil. I like to put my screen up against the edge of a wall like this and hold it with one hand and one hand on the coater. I'll stand up and I can control the angle of the screen while I bring the coater up. I'm going to demonstrate the technique to you. Before we actually use the full scoop coater we're going to use this empty one. We're going to use our round edge. We're going to center our scoop coater in the middle of the screen. We want to start about an inch to two inches away from the edge of the frame. When we touch the screen with the scoop coater, we're always going to maintain that contact because if we don't, then the emulsion is it's going to fall onto the floor and all over the screen. You'll want to touch it, maintain contact, and then we're going to bring the coater forward. When we do that, we're going to see the emulsion move forward. We're going to wait until we see all of it touching the whole length of the screen before we start to go up. This angle up here is going to help guide you how far to tilt the scoop coater. We've got a round edge. You're going to get centered, start about an inch up. We're going to place it on here, then we're going to tilt forward while maintaining pressure. Watch the emulsion go up. Still maintaining contacts, we're going to bring it up nice and smooth. You want to hear that sound. I'm going to stop about two inches from the top. One of these. I'm going to do one more on the front of the screen. So same thing. We're going to stop about two inches, bring it back to let the emulsion flow into the coater. Little wiggle and little scoop. If you do get a little buildup on the edge of your coat, you can take one of these cards and you can just give this a little scrape and that'll make the emulsion thin. We're not worried about this area of the screen because we're going to fill that with tape anyway. We just want a nice even coating in the middle of the screen. Now we're going to dry our screen. We need to do this in the dark. We want to also do it in the horizontal position with the bottom of the screen facing down. This is where I dry my screens. As part of my printing table, I built in a little screen storage area. In here, you can see there's little slots that the screens fit right into. They dry in here, and I don't put a fan on them. I use a small heater and a small dehumidifier. You don't need to do it this way, but I would recommend not using a fan. Just put it in the room or closet or anywhere dark, elevated on something on the four corners in the horizontal position. When that's dry, we're ready to expose. Now we're going to clean that out in the sink. You want to pay special attention to the edge. Clean it out as soon as you're done. 13. Film Positives: While our screens are drying, let's talk about films. The film is what we're going to use to make our stencil on our screen. You can either hand-draw your film or print it out on a computer. A film is made up of a clear plastic and an opaque black ink. When we coat our screen with emulsion, it becomes sensitive to light. The emulsion hardens into a stencil wherever light reaches it. The black ink on the film is going to stop the light from reaching the emulsion. That's why it's important for it to be opaque. After the screen is exposed, the areas that did not harden can be washed out with water producing our stencil. I have here a few different kinds of films. Some of them are hand-drawn and some of them are printed out with a computer. Let's start with the hand-drawn ones. You can use a paintbrush with India ink or a paint marker to do this, but you'd really just need it to be opaque. If your film is not opaque, some light is going to creep through your film and make it difficult to wash out your screen. You could also achieve the same effect by blocking out the screen with construction paper or anything else that's opaque. This film here is a combination of hand-drawn and computer-generated. This is painted with India ink, and then these screens are computer-generated that go on top. You can see how this all comes together. This is a four-color print. We have registration marks on here to show where each screen lines up. Here's what the final print looks like. Films can be saved and used again. You can wash your emulsion off the screen to put a different image on and then come back to that if you ever want to in the future. These are some examples of computer-generated films. You can output them from most any graphics program. Again, the most important variable of them is making sure that the ink that is printed on the film is a solid, opaque black. The best way to tell if your ink is opaque enough is to hold it up to the light. We will go more in-depth on this in the demos from making your film positive. 14. Light Sources: You will need a light source to expose your screen. The light has to be the right type to react with your emulsion properly. Light spectrum is measured in nanometers, and generally, a screen printing emulsion is going to be exposed between 380 and 420. An emulsions manufacturer will tell you which wavelength is needed to expose the screen properly. This first option is a readily available halogen work light. This will do the job, and it's probably the cheapest option. This is an LED black light. It's a little more expensive, but it's the right wavelength and it doesn't get hot. This light is called the metal halide light. It's what they have in parking lots and outdoor spaces, but print shops use these to expose screens because they're in the right wavelength and they're really powerful. They are the most expensive and cumbersome option though. There's actually another piece that goes with this. I would recommend either one of these lights, the halogen floodlight or the LED black light. Both of them will work fine. Just make sure you're using a dual-care or Diazo-based emulsion. 15. Exposure Variables: When we expose screens, there are several different variables at work that control the outcome. We've already learned about emulsion and light source. We're going to learn two different ways to set up and expose our film positives. We want to be consistent in the way we do things for every step of the process. Because if there's ever a problem and we need to troubleshoot, we can rule out different variables because we do them the same every time. I'm going to show you two different methods for doing this in the next section. 16. Hand made film - Glass Exposure: Let's start by drawing our film positive and then exposing it using the plate glass method. So I'm going to be working from this existing drawing. I'm going to take some painter's tape. I'm going to lightly tape down the corners so that stays in place. Then I'm going to take my piece of film, make sure I have some area around it. I'm going to tape that in place. Now nothing can move when I work on this. The goal here is to make your mark opaque. The key is that it has to be opaque. That's why we're using paint markers or India ink and you'll be able to tell by holding your stencil up to the light. I'm just going to trace my edges here. Now I'm going to switch to the India ink to fill in some areas with the paintbrush. India ink works really well. Hold this stencil up to the light to see if it's opaque or not. If you need to, go over some lines again with the paint marker or a paintbrush. Now we're ready to expose our screen. You will need a piece of plate glass, an eighth inch to a quarter-inch thick, at least an inch or two smaller than the inside dimension of your screen. The glass should rest on the mesh and not on the screen frame. Now that our screen is dry, it's time to attach the stencil. You can see that our screen is upside down now. This is the back of the screen and we're flipping our stencil over so that when we hold our screen up like this in the printing position, it's right reading. In order to hold our film flat while we expose our screen, we're going to put a piece of glass on top of it. But first we're going to take this piece of two inch foam and put it underneath the screen. You could do something else like a stack of paper or books for this process. But the foam works really good. We have our foam, we have our screen, we have our film positive. The next thing we're going to do is take our exposure scale and put it on the other side of the screen. Then we're going to put our piece of glass on top, sandwiching everything in-between, making it nice and flat. There's a formula about how far away should put your light to your screen. You measure the diagonal distance of your frame and then multiply that by 1.5. This is a 20 by 24 screen. I have a 31 inch diagonal, so the light should be 46.5 inches above the screen. If it's off by a couple of inches, it'll be okay. It's just a general guideline. I have my light rigged up above my screen at the right distance. We're going to turn this on and shine it through our glass, our film positive, and our emulsion. This is a 123 mesh and we're going to expose it for seven minutes. I know that seven minute is a correct exposure time because I use this exposure scale to figure it out. I'm going to show you how to do that also. We're going to start by getting both sides of the screen wet with water and then we're going to wash out from the back side of the screen. It starts to become lighter and you can see your image. As you can see, our image will start to appear. Everywhere where the light did not hit the emulsion, meaning where the positive was blocking the light from reaching it is going to wash out. Now we're going to want to wash out our exposure calculator all the way up until step 7. We want steps 21 through eight to wash out. We want to be left with steps 1 through 7. If we're off by a few numbers, there's a simple calculation we can do to get the right time. Follow the instructions on the exposure calculator. Hold it up to the light to make sure you got everything. Give both sides another quick rinse. If the screen is slimy on the front of the emulsion, it means that you are definitely underexposed. The emulsion has not hardened all the way through and more time is needed. Follow the instructions on the exposure calculator. Keep track of your exposure time so you have a chart to refer to if you're using different mesh counts. 17. Computer film - Adhesive exposure: We're going to need our film positive, exposure meter, light source, and spray adhesive. When we print from a computer, we want to optimize our settings to print the densest black ink possible. We're going to print in gray scale at the highest quality settings. The film needs to be as opaque as possible to block out your exposure light. I'm printing from Photoshop, but there are many other options. Use whatever gives you the greatest control over the printer settings. I use a 44-inch-wide roll printer, but you can do this with a desktop ink jet printer or a laser printer. Sometimes, if your image is not opaque enough when you print out with a computer, you can print out two transparencies and then double them up and tape them together before you expose. Now, we're going to learn another way to hold down our film positive to our screen. Instead of using a piece of plate glass, we're going to use some spray adhesive. Do not use permanent, look for something that says repositionable. You just need a little bit of spray adhesive to hold it on to the stencil. You want to try to use as little as possible so it will wash off the stencil easily. I like to hold it about two feet above the positive and lightly mist it so that the glue falls down onto it instead of spraying it up close. That should do it. Sometimes, the positive will look like this after you spray the glue on it. It usually does not affect the exposure though. I put down a sheet of cardboard so I don't spray directly on the table. Next, we place our film positive on our screen. Remember, we're going to leave enough area around the image so that we have room for the ink and the tape. We're also going to stick our exposure scale on the other side of the screen. For this method, I'll stand my screen up on the end and I'll have my light 46 and 1/2 inches away, because my diagonal is 31 inches on my screen. We're using a 137 mesh screen. I know our exposure is going to be 6 and 1/2 minutes because I've already run a test with my exposure scale. I'm going to show you how to use this after we wash out the screen. Our time is up so I'm going to take my film positive off. You can see there's adhesive left on the screen, that's why we want to put down as little as possible. We're going to be able to wash this off with some soap and a sponge. Take off our exposure scale and bring it over to the washout. We're going to get both sides wet. We should start to see our image appear. We want to wash out from the back side. I'm going to use some soap and a gentle scrub brush to get this adhesive. That's all you need. It usually comes off pretty easily so let's keep on washing out. This is the exposure meter I used. There are many different designs of these. This one is called a Stouffer scale. It works by exposing a gradient on the screen. You can see the numbers start to wash out. We want to see steps 21 through seven wash out. We want everything up here to be solid and these to be open. We're off by a couple of steps. There's a calculation we can do to bring our exposure up to the right time. You can see numbers 21 through eight have washed out of the screen, the numbers one through seven are solid. Another trick is to feel the front side of the emulsion to see if it's slimy. If it's slimy, then, your screen is definitely underexposed and you need more time. You want to hold it up to the light to make sure you've got everything washed out. This looks pretty good. We're going to let this dry and then we'll be ready to print. 18. Off - Contact: Before we start printing, I want to go over an important variable known as off-contact. Off-contact is the distance from the bottom of your screen to what you are printing on. So if it's this piece of paper, it's the distance between the paper and the screen. We don't want our screen to lay directly on what we're printing. We always want there to be a gap so that as we run our squeegee over, there's a nice transfer of ink down onto the paper and the screen comes back up. A lot of times, screens have a natural off-contact. This screen is directly on the table, not in the hinge clamps, and I can push down and there's about 16th of an inch gap. As we run our squeegee across, the mesh is going down and depositing the ink onto the paper, and as we go across, the mesh is springing up. That action is called the peel or the lift of the print. That's why we want our screen to be as tight as possible so that when we run the squeegee across and it goes down, it transfers the ink down onto the paper and the screen springs back up. Off-contact is necessary for a clean transfer of ink. When we put our screen into our hinge clamps, we get more off-contact. We can see the bottom of the hinge has about 16th of an inch on these ones. Some have a little bit more. The off-contact is higher here here than it is down here. So to compensate for that, we're going to put two pennies, which is roughly the distance under here, in the front of the screen. I'm going to take a piece of tape, put it on the pennies, and then I'm going to attach them to the two front corners of the screen. Now we have about an eighth of an inch off-contact around the entire image. A good amount of off-contact also will help the paper stay down as you print and not stick to the back of the screen. Sometimes, that's inevitable though, especially with thin papers, and you're just going to have to print it, lift up your screen, and peel it off. They do make more sophisticated kinds of table presses that keep the paper down with suction and little holes. But for printing on a board like this, a lot of times, just peeling it off the back of the screen will work just fine. 19. Intro to Printing and Registration: Now we're going to learn how to print and register the screens we just made. I'm going to show you a couple of different registration methods that you can use for different situations and materials. Remember, once you start printing, you want to have everything you need for your run within arm's reach. You don't want to be looking around for stuff while there's inking your screen. With water-based ink, the first time you put the ink in the screen and make the print, you got to think that your ink is drying in the screen and you don't want to walk away. Let's get into it. 20. PRINT Paper Stencil: I'm going to show you our first registration technique using hinge clamps and tape corners. We will need a paper stencil, a squeegee, an ink and stir and tape. For our surface, I'd like to use a piece of MDF that's three-quarter inch thick or a piece of this melamine that has a coated material on the top that's hard. That's what the table is made of. Basically, anything that's flat and rigid. You could screw directly into the counter-top also depending on where you're working. The first thing we want to do is tighten up our clamps, not too tight. That's about good. Then we can lift up our screen, and a lot of times these will just stay in place. If that doesn't work though, you can just grab the old can of ink and hold the screen that way. That works fine too. We're going to grab our paper, put our screen down and move it around until we get it where we want it. Lift that screen up without moving our paper, then we're going to take some tape and we're going to make four pieces. It's a good idea to lightly tape your paper in place while you do this. Now with the flat edge of the tape, we're going to line up to the edge of the paper, and we're going to make a right angle. We're going to do just this corner. We're not going to do the whole thing. We're just going to do one corner. Registering to one corner is more accurate than taping out the whole sheet. It's going to look something like that, then we're going to carefully remove our tape. As we print, we're just going to place these down right on our marks, bring our screen down, print, and everything will remain in the same place. The first thing I'm going to do is make up our ink. Already have a little bit in here and add a little bit more. I'm using this Golden brand acrylics. That is a heavy body acrylic, meaning it just has more pigment in it, it's a little bit thicker. I'm going to put some of this in here and then I'm going to add a little bit of water and a little bit of printing retarder. Printing retarder, they tell you to add about three and five percent. I just use about this much. All right, not too much. If I need more, if I see my ink drawing on my screen, I'll add a little bit more midway in the run. I'm going to add a little bit of water. I can't stress enough the importance of stirring your ink for at least 30 seconds before you start printing. It's still on the thicker side, but this ink feels good. Now we're going to set our off contact. We can see that because of the hinge clamps that goes underneath the screen over here is just a little bit higher, than down here. We're going to take some tape with the two pennies. I'm going to tape it right in the middle of the screen on the frame, so when I put it down, now our off contact is pretty even all along the way. We're ready to begin. We have our taping here here, so our ink is not going to go all over the place. We have our off contacts set and we have our registration in place. We're going to add a line of ink across the top. You don't want to add too much. You can always add more. Something like this will get us started. That seems pretty good. Even at that a little bit, our squeegee is about an inch bigger on each side of the image. If this is straight up, we want an angle about there. We have this off contact to overcome. We have to push down and then back, then lift up because we need the ink to touch down to the surface and then up. We're going to lift our screen up now. Remember we can also use our ink container. Put it right there, something like that. We're going to put our paper on our marks, bringing our screen down. You want to push too hard just enough to release the ink onto the surface. You're going to have to try a couple to get the right pressure. Every different material is different. On the first pass, I'll like to do two. Lift up this one stuck to the paper a little bit. There we go. The next thing you can do is a flood stroke, where you actually flood ink back this way. We're not printing it, we're just getting in the stencil in that mesh, and then we're going to do one pull. If you can do it in one pull, that's the best. Now you're going to have to do this a couple of times to get the feel for it, and to know how much ink you need, how much pressure, the angle, all of those things relate to the print. Eventually, you'll get your technique down. I'm going to flood. I can also flood this way. When I flood, I'm just printing very lightly, I'm not pressing down. I'm just going back and skimming the mesh and filling that stencil with ink. Lift it up. You're going to lift up quick too and you'll get a better release from the paper. Before I even look at the print, I'm going to flood it back. I'm going to rest my squeegee over here, lift this up and put my screen down that's flooded. I'm going to press down. I'm going to get my angle, go back, snap my screen up, so it comes off, and I'm going to flood it. Remember, floods first. Once I flood the screen, I don't really need any more ink. I can keep this up here. My stencil is already filled with ink. You can see how quickly you could produce a lot of something. If you have a helper, you could print even faster. But once you get the hang of this, it's a great way to make greeting cards or little gifts for the holidays. Sometimes you can print a stencil without flooding it. You're just going to have to see how your stencil overreacts. This one seems like you don't need to flood it, but you need to be printing consistently this whole time. Because remember the ink is drying in the screen the entire time. Just a matter of how slow it's drying. It's time to clean our screen, so I'm going to grab my card. I'm going to keep it up off the table, to all tape in here. I'm going to put my ink back in my container. It's going to scrape this up off here. Put it back in here, and you can save this stuff without any problems as long as it's in a tight container. Remember the paper stencil is a one-time use only, so make more prints than you think you need. We're going to flip it over. We're going to take off our tape, off contact, pennies, then we're going to peel off our stencil. You You really save this. This is what it becomes. Now we're ready to bring this over to the sink and wash it out.[NOISE] [MUSIC] 21. PRINT Screen Filler Stencil : This method is called the mylar hinge. We're going to use the tape corners registration. But I'm also going to show you a way, to line up the image using a piece of mylar. We're going to need our screen, squeegee, tape, ink, paint stick, and mylar or plastic. We have a nice clean, smooth surface. We're going to lay out a napkin. We're going to line on our screen up. It's going to roughly go somewhere there. This is a mylar material you can get at art stores. This is seven mil thick, but anything probably three mil or thicker will work. It's just nice because you can re-use this and wash it. We're going to start by cutting a piece of mylar a little bigger than your image so we can extend past your screen. Then we're going to tape one edge down making a hinge. We're going to flip this over and we're going to tape on this side of the hinge. You want to make sure that you have enough space here to be flipping this hinge back and forth while you're printing. When we print, we're going to print the first image onto the mylar and lift it up. Then we're going to fold it back. Then we can insert our napkin or a piece of paper. This is especially helpful for multi-color prints. You'll know where your image is going to land. You can check your registration with the hinge. Let's make our ink. I got my mozzarella container here. We're going to use this Speedball ball fabric ink. This is a metallic blue. You can see this is a pretty thick opaque ink. You could thin this out to make it print a little easier, but you're going to lose that opaqueness the more water you put in. We're just going to add a touch of water little bit just to loosen it up. Then we're going to add some retarder base into it. A lot of times an ink manufacturer will have their own retarder. We want to put whatever we're printing underneath the mylar, to have it react the same way and the same height on the hinge. I'm going to get the napkin roughly where it needs to be. Then what I'm going to do since this is fabric, is I'm going to lightly spray the back of this board, not the fabric. I'm going to lightly spray the back of the surface with a glue that's going to hold it down in place while we print. You just need a little bit of tack to hold it down. Use this spray adhesive that they have for t-shirts. Or you could use something light like this, re-positionable tacky spray. You want to read the label and see if it can be used for fabric. The advantage of the t-shirt one is, the adhesive doesn't really stick to the fabric. I'm just going to give it a light mist in the area of the napkin. Not much, just something to hold it down. So that when we put this down now, we can see it's going to stick much better. You don't really need a lot. You put down your fabric, you're going to make sure that you smooth all these bubbles out. But you don't want to stretch the fabric at the same time. Now put a line of ink across the top. Not too much. Put our hinge over, and elevate the screen with this paint can. We're just going to print this across the face of here, to fill the mesh with ink. Something like that. We do our first print on the mylar. Remember about that angle, not straight up, not 45. We don't need any ink because it's already in the stencil. We're just going to do one pass. All right, there is our tree. We're going to flood the ink back. You can either do a push or you can pull the ink, whichever one feels more comfortable. Then I'll raise my screen. I'm going to flip my hinge. Now I can make any adjustments if I want to move the napkin. You can see when you put down this hinge with the wet ink, it's going to leave a mark on your table. You can either just let that happen and clean it up later, or you can use a bit of tack on the surface and that'll dry the ink a little quicker. Run it too on the napkin for the first one. A lot of times you need to, you need a couple of strokes on fabric to really get the ink in there. Next, we're going to lift up our screen. Before we look at the image, we're going to flood it back. Now we can see that the ink is already drying a little bit on the screen. We're going to flood it back. This time we're going to go a little smoother with the ink. We're going to lay more on top to slow down the drying time. Check with my hinge. Everything looks fine. I'm just going to do one pass this time and see what it looks like. Then before I look at the image, I'm going to flood the screen. I'm going to go over once it fill the stencil and then I'm going to skim the top lightly and not press down into the mesh at all. This ink is very thick so I can put the screen in a vertical position. When I do that, I just rest a squeegee next to here on an ink container. You want to try to do everything on one pole if you can. Going over the image again and again, is going to make it progressively blurrier. Now it's time to wash the screen out. First, let's get all the out of there. Then take off my tape. Bring it over to your washing area, and rinse that with water. If you need to, you can use a soft scrub brush to rinse out any ink. 22. PRINT - Hand Drawn Positive : This is everything we're going to need. Our screen with our image burnt into it, our tape. This is the box we're going to be printing on. We can print on it flat and then fold it up. Our squeegee, a spray bottle filled with water, our ink that stirred up already, and our set of hinge clamps. Let's start by taping up our screen. We also want to tape up our exposure scale. Remember to try and keep all the tape flat so that your squeegee will roll over it with no problem. For this print, I'm going to use some opaque Jacquard screen printing ink, existing color. I'm just going to add a little bit of glycerin to slow down the drying time. Now, we're going to lift up our screen and place our box underneath. Once we get the image where we want it, we're going to lift up our screen carefully not to move the box underneath and we're going to tape this down in place. Next, we're going to set up our registration system. Last time we used tape corners. Instead of using tape corners, this time we're going to actually take a piece of cardboard the same height as this, and we're going to put two pieces here and two pieces here. That way, when we register, we're not registering by sight, we're registering by feel. So we're going to put it down and lock it into these tabs that are going to be taped down onto the table. That way your print is going to come out in exactly the same location every time. It's a good idea to use the same material that you're printing on to make your registration marks because it's going to be exactly the same height. I want to get the flattest edge possible. So I'm going to cut right from here. Now, my factory edges here, I'm going to mark that so I know that's nice and straight. Now, I'm going to take these down right on the edge of the cardboard so the two meet perfectly. You can use any kind of tape for this. I like to use painter's tape because it's easy to remove. Try to tape pretty close to the edge of the cardboard. Then I'll hold this down and I'll butt this up right against it. We want to make a right angle so that we're locking it into a corner each time. Don't put tabs all around the sides, just two sides. Now, we can remove the tape we put the hole down the box in place. We're going to put these down on the bottom tabs first. Then we're going to slide it over and lock it in, to this corner. You can see all the tabs are touching. This is especially useful when you're printing paper stock with multi-colors. You would make these tabs out of the same paper stock that you're printing with. We need to raise up our off contact. So it's about a 16th of an inch or an eighth of an inch off of the surface of the cardboard. In order to do this, we're going to take three quarters and tape them to the bottom of the screen. That seems to be about the right height. With our registration system in place, we're ready to print. We're going to take our ink and give it a good stir. At least 30 seconds. I know that seems like a lot, but we want it to be nice and loose and that will make our printing much easier. I'm going to put a line of ink up here on the top of the screen. Remember, we can always add more, so not too much. That's about right. We're going to smooth it out. We're going to get some ink ready. Make sure we have enough to cover the whole print. We're just going to do a print and get the ink in the stencil. This is different than the flood where we cover the image with ink to keep it from drying. Make our first print. Remember our angle is going to be something like that. We don't want to press down too much. I'm just going to do one. We'll see what it looks like. Pretty good. Now, the next one. We're going to go down into our tabs and then over. Print. Then we're going to flood the image back and coat it with ink. Once you get the hang of this registration system, it's actually very fast. If you were doing a large print run, you could have someone else loading and taking off the paper and you could just be printing. 23. PRINT - Computer Positive: Our screen is dry, so we're going to tape it up into our exposure meter. We are going to print the paint stick. First thing we're going to do is line this up under the screen. Now, when you adjust this, you could adjust the screen in the clamps, but I like to adjust just what you're printing on. This way, this stays locked in solid and it's not going to go anywhere. That looks pretty good, so I'm going to carefully lift up my screen. I am going to take the paint stick in place. We will make a corner using two paint sticks because they are the same height and have a nice straight edge. This will lock them into place while printing. We are going to set our off-contact by using another paint stick. Now, the screen is the same height as the paint stick. But remember, we still want a little bit of liftoff, so we're going to put a penny underneath here also. We have about a 16th of an inch off-contact, and that's going to work. A little bit of red. We have set up the print and we have everything we need to close by. We could do a test print on a piece of paper, but I have so many paint sticks and I'm just going to do a test on the paint stick. But if you wanted to do a test print, you would put the paint stick down and then the piece of paper on top of it. If you didn't do that, then this distance would be too great. I'm going to be using this little guy here and because it's such a small print, we don't need a lot of ink at all. We're going to pull the squeegee in this direction. Lift up the screen a little bit, flood our image, drop it, and we're just going to do one pass. Before we look at the paint stick, we're going to flood it back so the ink does not drive too fast in the screen. With a thin stencil like this, one pass is definitely sufficient. If you do multiple passes, you run the risk of making it blurry. You can see once you get this setup, you can really print a lot of things in a short amount of time. Sometimes, when you flood a screen, you only need to flood it once like this. Other times, you're going to flood and do a heavy flood like this so the ink does not dry too fast. If you flood too much ink into the stencil, it will actually cause it to blob out and make the image blurry. There's basically too much ink in the stencil. This is the back of the screen and you can see that there's just a little bit of ink filling the stencil. If you start to build it up too much, it will become blurry. If one of these lines starts to get clogged, you can wipe it out from the top side of the screen with a little bit of water. Sometimes, wiping the back of the screen will actually create more work in trying to clean the screen off and get it back to printing cleanly. I will spray some water on a cloth, and then I'll wipe out the image, and then I'll print it on a test piece of paper. Now, when you do this, the image might be a little bit blurry, but just keep on doing test prints until it becomes sharp. Now, take the tape and ink off and wash out your screen. 24. Outro: Congratulations on finishing all your lessons. I hope you enjoyed your time printing with me. I've enjoyed teaching you. We covered lots of material for making paper stencils to what off contact is. If there's anything I would like you to take away from this class, it's the diversity of materials you can print on and the different directions that you can take screen printing in. I'm excited to see what kind of projects everyone comes up with. Upload your project to the project gallery on the class page so we can all take a look. Feel free to contact me with any questions or troubleshooting. If you liked this class, please leave a review and follow my profile. Stay tuned for some more exciting lessons in the wonderful world of screen printing. Bye.