Soft pastels have high concentration of pigment
I love art materials and I love experimenting with them. In traditional Japanese woodblock printing, the printers used powdered pigments. Nowadays watercolors and gouache are readily available, so I have been using them, also considering using powder pigments can be harmful to my health.
But depending on the brand, paints in tubes behave differently, and you can go through lots of them quickly when you print large surfaces.
When I came across soft pastels, and learned that my daughter uses them at school with water, I started wondering if I could turn them into watercolor. Here are some facts about soft pastels.
Quality soft pastels have high concentration of pigment.
Hard and soft pastels are made of pigment, chalk, and binder.
There is a large variety in range of softness/hardness within soft pastels.
They come in hundreds of colors.
Dust of some pigments can be harmful to your health if inhaled.
Just as an experiment and not as a long-term solution, I have made a few watercolors with my cheap hard (medium?) pastels. I used Mungyo Soft Pastel but I believe you will get a better result with softer, quality pastels such as Sennelier or Schmincke.
I will call these scraped pastel sticks "pigment" in below recipe.
1 part mixture A
1 part pigment (adjust accordingly)
I have only mixed them with a stick, but ideally they should be mulled with glass muller or ground in mortar and pestle to get rid of any grainy texture.
It does not quite behave ideally like watercolor paint and leaves streaks, or maybe it dries quicker? But this may have something to do with the fact that I did not grind the pastel properly, and more liquid may have needed. Keeping in mind that this was the cheapest kind of pastels, I think there's a potential here. I now know that I could make a color that I may not be able to achieve with a tube of gouache or watercolor, by using a quality pastel.