This is what masking fluid looks like…. it has many names and there are a lot of brands, too. I’ve been using this brand for a while and it’s my favorite. Since it has the potential to really mess up my brush, I have some brushes that I really don’t care for set aside to use for painting the masking fluid on.
This is what the painting looks like with the masking fluid painted on. When it dries, it’s a thin layer of rubber that lets you paint over it without affectiing what’s underneath. This way, I can paint the background and the ground without having to worry about painting around the characters. Also, for a wash, the entire paper will be made very wet so that the paint runs. A wash would be impossible to do if the characters were not masked first.