Favorite Artist Project: Surprises! Inspiration! (and a couple questions)

First, gratitude for Elisabeth's inspiring and informative class. I shuddered when I heard "black oil paint," but -- bless her! -- Elisabeth made the project more accessible. I made a small, maybe 5x7 inch splot of black oil pastel. I made two Klee-ish drawings inspired by images in my Klee book. (Of course I have one! LOL!) The others are from left-over paint watercolors, some on plain paper and some on the worst watercolor paper ever (VIVART to drop a Name. I use it only for left-over paint paintings.)
Also, I very much appreciate the slide show on Klee from Elisabeth as well as the others in "Artist-Inspiration" classes.
Below are my three first attempts to use the transfer method a la Klee. These were all on white, quality printer paper, letter-size cut in half. The paper had splashes of left-over watercolor paint which I like to save for collage. I was cautious.

A first look at what was possible using this technique, and I was hooked. Just plain left-over green watercolor on paper, but almost magically transformed.

I rolled a piece of wired tubing over the back of this piece. So easy and fun!

Again, just left-over paint on plain paper. rubbed a ruller across for texture then drew some random lines. with the end of a paintbrush. I can admire Klee's artistry with this method as I see the challenges and possibilities.
Next I did image transfers with more left-over watercolors. I used these to play with making drips and wet-on-wet puddles. These are on that "bad" watercolor paper mentioned earlier. I didn't think any of these were more than pieces to save for something else. All about 4x6.

Drippy left-over autumn colors.

Mish-mash-of wet-on-wet watercolor.

II didn't even like this one until after the image transfer, and now I really like it!
Finally, here are the two images I drew. I drew the angel with pencil then put that on top of the black and re-drew the angel into the black. I painted the image I got from my black ink. It's called "Forgetful Angel," (1939) and appears in a chapter about "Angels, Saints and Demons," with spiritual themes in Klee's art. (This may have been during a time of illness for him.) The other image, was inspired by "Senecio," (1932) a painting, and my rendition looks more like a cat than Klee's portrait.

Judy Williamson-Batson
--Meanwhile, the next day, got curious: Would water-based-pastels that look like the oils but say "water," not "oil," work as a base for image-transfer? Created a 2" x 4" spot of dark purple. Used plain scrap paper, one white, the other colored and got results.

The spot was small, soI had to move my top pieces around quite often for random lines and rubs. Then I cautiously did some watercolor on the white on with a resist from the base color. No bleeding. Added other marks to both, and the purple did not repel Posca or gel markers. The one layer of the pastel marker didn't need refreshing for these two small pieces.
BIG QUESTIONS: 1.) Does either water or oil pastel need a fixative to stabilize it from rubbing off, or does it eventually dry? 2.) what is the difference between oil and water pa stels?