The challenge whites, draw something that is white. The very first thing I thought of was snow. Do a snow scene but then I thought go somewhere else. Like the ocean, so I drew a beach chair. That was a fun place to go. Drawing into black powder to create a white image is very challenging. I kept putting less and less powder on the glass.
The beach scene made me thing of white birds, then I thought of a snow owl. It is hard to draw white and then have shading that is soft and not hard. I had a hard time with this and had to soften the shaded places with my finger. I can tell what it is but I think it can be improved.
When I think of white I think of boats. I love photographing boats. I had a photo of a boat from Sandpoint, ID when I visited last summer. I loved the sailboats on the water. So, this is my version of what I saw. The sails runs off the page because I wanted to try and apply all the powder at once. Somethings work some don't, but over all it was fun.