When I draw I usually just take a plain piece of paper and draw in black and white, so to say. It is easy and straight forward, and it feels good. Even though I like the black and white it can sometimes me nice with maybe one colour to work with to get some other tone to work with. I made an experiment. I painted acryliv colour on a plain paper, a bit thicker than usual, and it turned out really good, it did not crease much at all. And then I tried to sketch with my waterproof pencils on this surface. well here is the result.
I also tried out the aqua brushes on this surface as well, that got a bit messier. I had already figured out it would not stick to the acrylic surface so black lines and the thicker lines are made up of the waterproof pencils, the colour though is the aqua brushes.
In a few places I have just played around smudging the aqua brushes. The colours are pretty transperant and as the acrylic foundation is a yellow colour a few colours was really hard to use.
I think I will continue to use the aqua brushes where they are supposed to be used but I will absolutely keep on using the waterproof pencils like this. The surface has less friction than an ordinary paper and it is a fun way to change your way of working.