How to Use Masking Fluid in Watercolor: Tools, Tips & Techniques

1. Introduction: Hi. In this lesson, I'm going to talk about masking fluid, what it is, how we can use it, what tools are best for applying it, and the techniques that can help you create different effects. I hope you find this lesson helpful and maybe even pick up some inspiration ideas to try in your own paintings. Let's get started. 2. What is Masking Fluid: Masking fluid, also called liquid frisket, frisket or drawing gum is a liquid latex base product used to protect certain areas of your watercolor paper that you don't want to paint over. It's most often used to preserve small details, highlights or intricate shapes that would be difficult or too time consuming to paint around. Once the masking fluid dries, it forms a rubber like layer. That resists watercolor. After you've finished painting and everything is completely dry, you can peel off the masking fluid to reveal the untouched area underneath. This area can stay white or you can paint over it later. It's entirely up to you. Masking fluid can also be applied over a dry layer of paint. In that case, when you remove the masking fluid, the previously painted color underneath will be preserved. There are generally three types of masking fluid, colorless masking fluid, and this one dries clear or white on the paper, tinted masking fluid. It has a light color, usually yellow, light blue or gray. That makes it easier to see on the paper. This is useful if you have trouble keeping edges neat or simply want to better see where you've applied the masking fluid. The gray tinted version is the darkest one and it's especially visible. Don't worry, the color of the masking fluid will not stain your paper. Once you remove the masking fluid, the paper underneath will remain white. And there is also the third kind of masking fluid, permanent masking fluid, and this one is not removable. It can be used to permanently protect certain areas of the paper and can even be mixed with watercolor to isolate color from later layers. However, once applied, it cannot be lifted. So use it with caution or don't use it at all. I have never used this type of masking fluid. Personally, I use the second one, regular removable masking fluid, and my favorite one is from Windsor Newton, which has a slight yellow tint. 3. Tools For Applying Masking Fluid: Let's now take a look at the tools I'll be using in this lesson and that you can also use to apply masking fluid in your own work. We have many possibilities. For this lesson, I'll be using my favorite masking fluid from Windsor Newton, yellow tinted, I will also demonstrate Canelias masking fluid which comes in a marker with a special applicator. Another good option is the drawing gum marker from the Pibo brand. We will take a look at that too. Other things you will need are a container with clean water, a cup from an old masking fluid or anything else that you can use to pour some masking fluid into and a bar of soap. This is a must have, and I will explain why in a moment. Then we have also application tools. You can apply masking fluid with a wide range of tools such as cheap synthetic brushes, a water brush filled with soapy water, a deep pen, silicon shaper brush, embosing tools a toothbrush, a ruling pen, a toothpick, pin, paper clip or needle. There are a lot of different tools that you can use. You'll also need a regular eraser or a rubber masking pickup tool to remove masking fluid on dry, masking tape, cling film, and a ruler. Now let's go one by one and explore what we can create using masking fluid. 4. Brush, Full Shape, Precision: We'll start with the simplest method using a regular brush to cover a full shape with precision. Time you use masking fluid, steer it gently. Don't shake it. This helps mix in any pigment that may have settled at the bottom if you're using a tinted masking fluid. Steering wakes the fluid up and ensures even application. Avoid leaving the bottle open as exposure to air causes the fluid to dry out and form clumps inside. I usually pour a small amount into a separate container, and I usually use an old cup from an old bottle of masking fluid, and then I quickly close the main bottle to protect it from oxygen. Some artists suggest storing the battle upside down as it seems to keep air out more effectively and helps preserve the fluid longer. I always forget to do that and I just keep mine upright. But it's a helpful tip if you remember. Let's start by drawing a quick shape. Imagine you're going to paint something where you want to protect the shape and begin with the background. Instead of carefully painting around it, you can cover the shape with masking fluid and paint freely over the rest. To do this, use an old or inexpensive synthetic brush. Never use your good brushes. No matter how careful you are masking fluid will eventually damage any brush you use for application. That set, there is a trick that will expand the life of your brushes significantly. Before dipping your brush into masking fluid, first, wet it with clean water and then rub the bristles several times on a bar of soap until they are well coated. The soap creates a protective film over the bristles, helping to prevent them from sticking together when the masking fluid dries. Since masking fluid dries quickly and can glue the bristles permanently, this step is essential. The bristles stick together, it's nearly impossible to separate them again without damaging the brush. Always use cheap brushes and always use soap before applying masking fluid. Now that the brush is coated with soap, we can dip it into the masking fluid and begin applying it to the paper. As you apply, try to be very careful and precise. The shapes you create with masking fluid will be very prominent later, and the edges will be clearly visible. The neater and smoother your application, the better the final result will look. Follow your pencil lines slowly and carefully, filling the entire shape. Be generous with the amount of masking fluid. The layer should be thick enough to fully cover the area. Make sure that there are no bubbles or tiny pinholes, as watercolor could seep into those spots and stain the paper underneath. After about a minute or two, rinse your brush in clean water, blood it on a paper towel, and repeat the soap process. Deepen water, rub on a bar of soap, and continue applying the masking fluid. It's important to clean your brush frequently while working. Don't let masking fluid sit on the bristles too long. It can start drying and may ruin your brush. Keep working carefully and filling the entire shape. Once you're finished, wash your brush thoroughly in water and blood it dry on a paper towel. If you followed the soap and cleaning method, your brush should remain soft and undamaged. If not, well, one bad use is enough to ruin a brush. I have several old brushes that I use just once for applying masking fluid, and I didn't use soap, so here is the result. But as you can see, a few simple steps can protect your brushes easily. Once applied, allow the masking fluid to dry completely, depending on how much you used and the size of the area. Drying time may vary from a few minutes to even several hours. In my case, the masking fluid dried in about 20 minutes. Before you begin painting, gently touch the masking fluid with your finger to make sure it's completely dry. If it's still tacky or soft, you will feel a slightly tender surface or it may stick to your fingers. When masking fluid is dry, will also notice a slight color change. It usually becomes a bit darker than when it was freshly applied. Now that everything is dry, you can start painting around the masked shape. Since the shape is well protected, you don't need to be careful about painting around it. You can even paint directly over the masked area and nothing will happen. The masking fluid will resist the paint completely. You paint, you will notice that some pigment may sit on top of the masking fluid. It's a good idea to remove that excess paint while it's still wet. It's not strictly necessary, but it helps avoid unwanted smudges. Here is why. If the masking dries on top of the masking fluid and you later rub it off, it might smudge into the clean white area you are trying to protect. Once your painting is dry, it's time to remove the masking fluid. I use a rubber pickup tool which works wonderfully. You can also use your fingers, the sticky side of masking tape, a bowl made of dried masking fluid scraps. Whatever tool you use, make sure the background is completely dry before removing the masking fluid. Otherwise, you risk damaging the surface or smearing the paint. For me, the rubber masking pickup tool is the easiest and cleanest method. You can see, there is a small spot of paint on one of the leaves. I probably wasn't careful enough or perhaps there was a tiny pinhole in the masking fluid through which the paint seeped. When this happens, I usually use a scrubber brush. Dip the brush in clean water, blot of the excess water on a paper towel, and gently wrap the stained spot to activate the paint. Then lift it with a clean paper towel. I usually do this before I start painting the main shape as a part of the cleanup. I also use the scrubber brush to smooth out edges if they are too rough or not as clean as I want them to be. For that, use a damp scrubber brush gently rub along the rough edge and left the paint with a paper towel. This process will slightly blur the edges, but that's totally fine. Once you paint over the shape, the new edges will look clean and intentional. Just remember the quality of the masked edges entirely depends on how careful you were during the application stage. Precision early on makes a big difference. 5. Waterbrush, Full Shape, Careless: Let's do some masking technique, covering a full shape, but this time we will use a water brush filled with soapy water, and we will apply it less carefully to show why precision matters. Because the brush is already filled with soapy water, you don't need to use a bar of soap, although you still can for extra protection. Before dipping the brush into the masking fluid, squeeze the brush slightly so the soapy water coats the bristles. This will create the same protective layer that we applied manually with the bar of soap earlier. The result of using a water brush versus a regular brush is the same. The only difference is how we apply the soap. With a regular brush, we coat it using the bar of soap. With a water brush, the soap is inside the brush itself. This time, I'm applying the masking fluid without much care, going over the pencil lines. I want to demonstrate that this stage is crucial for creating clean, beautiful shapes. If you're not careful enough, it will be difficult to fix the edges later. Once you've applied the masking, squeeze the water brush again to rinse the bristles, et everything dry completely, paint the background as before. When dry, remove the masking fluid. Now take a look. You can clearly see every little mistake I made. I went over the pencil lines and now the shape looks messy. It will be hard to fix because even if I try to repaint the background around the shape, it's unlikely I will match the color perfectly. It will be obvious that I tried to patch something. Again, be extra mindful about clean accurate edges when applying masking fluid. 6. Brush, Only Edges: Next, let's try another method using a brush, but this time we will only mask the edges of a shape. It's not always necessary to cover the entire shape with masking fluid. If the shape is a bit larger, I often just mask around the edges. This saves time and fluid and still protects the shape from paint bleeding into it. Of course, with this method, you have to be a little more careful not to let paint drip into the unprotected middle, but it's not too difficult with some control. Use this edge only technique mainly for medium sized shapes. If the shape is very small, I cover the whole thing, and if the shape is very large, I use another technique which I will show you at the end of this lesson. Now that the edges are protected and the masking fluid is completely dry, we can go ahead and paint the background. Once the background is dry, you can remove the masking fluid and either paint the main shape or leave it white depending on your original intention. 7. Masking Marker: Let's now explore a few different tools you can use to apply masking fluid creatively and precisely. Here we have a masking marker from the PBO brand. It comes with a removable tip and to use it, you simply press the tip slightly and hold the marker perpendicular to the paper. These markers are available in different tip sizes. I think the one I have is a small one. The masking fluid only flows out where the tip touches the paper, so it's easy to create very precise lines and dots. It works more like a pen and isn't ideal for filling large areas or entire shapes. Because the layer is very thin, it dries quickly, often within a few seconds and you can paint over it almost immediately. After removing the masking, we get a nice clean result, a great option for fine details or even hand lettering. This tool opens up many creative possibilities in your paintings. 8. Embossing Tools, Lines and Dots: Step, we have embosing tools which are commonly used in nail art and papercraft. They have small metal balls at the tip and come in various sizes. Because they are made of metal, they are very easy to clean, even if masking fluid dries on them. To use them, dip the tip into masking fluid and apply directly to the paper. You can use them to create lines, dots or other decorative elements. In this example, the line is wider at the beginning and becomes thinner towards the end, a natural effect of the bowl tip. This is perfect for things like flower stamens or shooting stars in a night sky. Let's look at the result. Clean, elegant lines and dots. 9. Embossing Tools, Stamens: Let me show you a quick demo using an embosing tool to draw flower statements. I start by dipping the tool in masking fluid and I begin with the anther, the wider top part, then draw the filament downward. Since the embosing tool naturally creates a wider mark at the start, it's ideal for this kind of shape. I'm just drawing random statements, pretending this is the center of a flower. Once the masking fluid is applied, I paint over it, let it dry, and then remove the masking fluid. Can you imagine how tricky it would be to paint around shapes this small? That's exactly why masking fluid is such a helpful tool. Now that the stamens are masked and revealed in white, you can paint them with your desired colors. 10. Embossing Tools, Shapes: Can also use embosing tools to protect entire small shapes. However, because the tools are relatively small and only hold a bit of masking fluid at a time, they are not ideal for larger areas. It would simply take too long. But for small or detailed shapes, embosing tools work wonderfully. They come in different sizes, so you can use a larger tool for slightly bigger shapes and switch to a smaller one for tight corners or delicate tips. In this example, I'm applying masking fluid to a shape using both a smaller tool for the tip, a larger tool to fill the rest. Once the masking fluid is dry, we can paint over the area and let it dry again before removing the mask. Once everything is dry, we can remove the masking fluid and see the result. I can already spot some jagged edges, so in this case, I would likely reach for my scrubber brush to gently smooth them out. H 11. Masking Fluid with an Aplicator: Next let's take a look at the battle of masking fluid bicenelia. It comes with a special applicator tip similar to a very thin needle. In theory, this should allow us to create fine clean lines. However, in practice, the fluid is quite thin, and as soon as I turned the battle upside down, a blob of fluid fell onto the paper. Even without squeezing the battle, the masking fluid flows down irregularly, making it hard to control. The shapes I get are random and unpredictable. There is a needle attached under the cup, which you need to insert into the applicator when closing the battle to prevent clogging. Now that the masking fluid is dry, I will apply some paint, maybe using a bit of negative painting and then let it dry. As you've probably noticed by now, this tool is quite difficult to work with for me, of course. It's unpredictable and I wouldn't use it for regular paintings. Maybe it could be useful for some abstract effects, but if you need fine clean lines, there are better tools, and I will show you one in just a moment. Everything is dry, so let's remove the masking fluid, and as expected, the result isn't great. 12. Dip Pen, Lines, Veins: Here is a much better way to create fine lines. Use a deep pen. Dip the nib into masking fluid and before applying it to your painting, test it first on a scrap piece of paper. Sometimes the first stroke can release too much fluid and turn into a big blob. Make sure that the masking fluid is flowing evenly from the nib. With a deep pen, you can draw straight lines, wavy lines, even dots depending on the nib and how much pressure you apply. The more pressure you apply, the thicker the line. Lighter pressure gives you finer lines. In this example, I was aiming for even consistent lines. You could use this technique, for instance, to preserve light veins in a dark leaf or for any other fine detail in your artwork. I wasn't super precise here, but I think you will agree that the lines created with the deep pen look much neater than those made with the ineliar applicator. 13. Silicone Shaper Brush: Other tool you can use for applying masking fluid is a silicon shaper or silicon brush. This tool is very easy to clean because it has no bristles. The tip is made entirely of silicone. To use it, simply dip the tip into the masking fluid and apply it to the paper. Silicon shaper brushes come in many sizes and shapes, making them useful for a variety of effects. After use, just let the masking fluid dry and peel it off. That's all it takes. In my example, the shapes are created were quite small, and this particular brush was a bit too large, so the edges weren't very neat, but it's still a useful tool to have, especially for larger shapes and bold strokes. 14. Ruling Pen, Lines: Step is the rolling pen a fantastic tool for creating lines, especially straight lines. A ruling pen has an adjustment screw at the top and two metal blades that hold liquid between them. You can use the screw to adjust the width between the blades, narrower for fine lines, and wider for thicker lines. Once you've adjusted to your preference, dip the rolling pen in masking fluid and you're ready to go. Always test it on a scrap piece of paper to make sure that the flow is smooth and consistent. You can use a ruling pen to create wavy lines or painted with a ruler for clean straight edges. When using a ruler, try placing small object like a coin or eraser under each end of the ruler to slightly raise it off the paper. This reduces the risk of smudging if the ruler shifts while the masking fluid is wet. Alternatively, you can simply lift the ruler up slightly on one side. Now, let's apply some colors and see how it looks. 15. Masking Fluid on Dry Paint Layer: So far, we've applied masking fluid on white paper. But did you know that you can also use it on a dry layer of watercolor? Here's how apply your first layer of paint and let it dry completely. It must be bone dry. Once it's dry, apply masking fluid over it. Here I'm using a ruling pen, but I will also switch to a deep pen and embossing tool to create some shapes. Let's say grass. The idea is that the masking fluid will preserve the color underneath. So when you apply the next wash, those areas remain the color of the previous layer. You can repeat the process, apply the paint, let it dry, mask areas to prevent it, apply more paint. It's a lot like negative painting, but instead of carefully painting around the shapes, you're masking them out. Once everything is dry, you can remove the masking and even add more paint if needed. One thing to remember, masking fluid can lift some paint when applied over dry layers depending on the paint and paper you're using. So it's a bit tricky, but it's a great technique to know about. But 16. Toothpick: Tool you can use is a toothpick. Just dip it in masking fluid and to draw directly on the paper. It's great for creating sharp details like, for example, cactus spikes. Admittedly, it can be a bit tricky to create perfectly straight lines, but with a little bit of patience, it's totally doable. A toothpick works similarly to an embosing tool. The line is usually thicker at the beginning and thinner at the end. In this demo, I've imagined a simple cactus shape and use the toothpick to draw spikes. Let's add some color. You'll notice that I'm using the same technique I showed earlier with the fur. I leave the edge of the cactus unpainted, and then lift some paint around it to create a glowing edge. Once the masking fluid is removed, you can also go in and add color to the spikes, if you wish. And that's another great way to use masking fluid in your paintings. B. 17. Needle, Pin, Paper Clip: Take a look at a few more tiny tools that can be surprisingly effective a needle, pin, and paper clip. Dip the tip of a paper clip in masking fluid and use it to create fine lines, dots or small shapes. You can do the same with a pin. To make it easier to hold, stick the pin into an eraser and use the eraser as a handle. The pin can help you draw delicate lines, swirls, or highlights. A needle works similarly perfect for tiny details. Of course, this technique isn't meant for masking large shapes. It's best for minute highlights like the sparkle in an animal's eye or tiny reflections, small tools for small jobs. Now I will feel this rectangular shape with abstract colors, and here is the result. Subtle and effective for those little finishing touches. 18. Splattering, Toothbrush, Brush: Let's explore how to splatter masking fluid for texture and special effects. I'm starting with a toothbrush. Since this technique can be messy, I protect the surrounding area first. Dip the toothbrush into masking fluid, then rub your thumb across the bristles to flick the fluid onto the paper. Test this first. You may get large blobs if there is too much masking fluid on your brush. That happened to me here, but it's not a problem. If needed, you can always remove the unwanted blobs after they dry. You can also use an old brush or cheap synthetic brush, dip it in masking fluid and tap your finger on the handle. Tap the brush on another brush or pencil or bend the bristles back and release them for quick flick effect. Each technique gives a slightly different result. The toothbrush gives you tiny grainy dots, perfect for sand like texture, and the paint brush creates larger random spots reminds me of stars in the night sky or falling snow. Here I tried to suggest an aurora. Once the paint is applied and the masking removed, you can also glaze over the white spots to add more color if needed. Here is a fan bonus. It's not about masking fluid but masking tape. I take small pieces of tape and arrange them on the painting to create a shape. Here I made a star. Then using a damp magic eraser, I gently lift the paint. In this example, I used too much water, so the edges aren't very sharp, but that's okay. It's just a playful little test. I repeated the same technique vertically to enhance the star shape, a fun trick for your toolbox. 19. Masking Fluid on Wet Paper: Here is something unexpected using masking fluid on wet paper. If you ask most watercolor artists whether this is possible, many of them will say, absolutely not. And I was one of them for a long time. The common advice is, don't do it. The fluid will soak into the wet paper and tear the surface when removed. But is it true? Let's test it ourselves. I begin by applying a water glaze, and then I apply masking fluid directly onto the wet surface. You probably can't see it clearly, but the masking fluid spreads in the water almost like watercolor paint. Once it's dry, I apply a wet and wet blue wash over the top. After drying completely, I remove the masking fluid. Surprisingly, it comes off cleanly, just like it would on dry paper. The effect, beautiful, soft, irregular white shapes with fuzzy edges, they remind me of clouds. This technique is very unpredictable, but the results can be stunning. Said, I want to warn you. This technique is risky and may not work on all papers or with all masking fluids. If you want to try this in your own painting, test it first on a scrap of your specific paper, use your usual masking fluid and be prepared for mixed results. Success of this method seems to depend on a number of factors, the type of paper, the brand, and thickness of masking fluid, possibly other environmental conditions, too. But the takeaway is it is possible to apply masking fluid on wet paper, and sometimes the result is really beautiful. There are some artists who actually use this technique in landscape paintings. 20. Leaving White Edges - NO-NO: Let's take a look at something I've often seen in beginner paintings. I'm sketching a quick example, a fake rose just for the demonstration. These are the petals and I'm applying masking fluid along the edges of each petal. The intention here is to protect the flower and create a kind of barrier between the flower and the background. So far, it makes sense. The edges are protected, and now I can paint freely. I begin with the flower, then move on to the background. I don't have to worry about the petal colors bleeding into the background or the blue green background creeping into the petals because the masking forms a nice clean barrier, right? Once the painting is finished, I remove the masking fluid and alla. Beautiful painting, right? No, no, no, no, no. Unless your goal was to create a stained glass effect, and maybe now you want to fill those white outlines with black, or you simply like the look of white edges around the shapes, which is totally fine as a stylistic choice. This isn't the intended purpose of masking petal edges. We don't mask edges to leave a white outline. We do this so we can paint the background freely. But then we remove the masking and paint the full shape, including those masked edges. 21. Protecting Big Shapes: Finally, let me show you a useful technique for protecting larger areas, a great way to save on masking fluid. Let's say you're painting on a larger sheet and want to preserve a big shape. Sure you could mask the whole area with fluid, but that would take time and use a lot of product. Here is a better way. Take a piece of cling film or plastic wrap that fits within the shape you want to protect. This is just a demo, so my shape is small. Use masking tape to secure the plastic wrap inside the shape. Make sure not to go over the edges with the tape. Keep it fully within the outline. Now, most of the shape is protected with the plastic wrap and masking tape. Next, apply masking fluid along the edges of the shape using an old brush. Be sure to paint over the masking tape slightly to seal everything and prevent leaks. Once the masking is dry, paint the background freely. When everything is dry, remove the tape and wrap, and your shape is preserved. I wasn't too careful here, so I smooth out the edges afterward with a dump scrubber brush. Let me show you how I used this method in a real piece, my painting a new adventure. In this painting, I needed to protect a large butterfly. I could have masked the whole shape, but that would have required a lot of masking fluid. Instead, I did the following. Took a piece of plastic wrap and cut it roughly to fit inside the butterfly's shape. It doesn't need to be perfect, just enough to cover the central area. Taped it down carefully using masking tape, making sure to stay within the pencil lines. And added an extra layer of protection using a cutout from a sheet of copy paper taped in the same way. Then with an old brush, I applied masking fluid around the edges overlapping the masking tape to fully seal the butterfly. The result, I fully protected large shape with minimal masking fluid used. 22. Quick Summary: So to sum up, there are many ways to use masking fluid and just as many tools to apply it from brushes and pens to markers or even pins. I hope this lesson gave you some new ideas and inspiration for how to incorporate masking fluid into your watercolor paintings. Thank you very much for watching and happy painting. Bye.