You can sketch in it, erase lightly in it (with a rubber eraser), use watercolors, collage, but I don't recommend acrylics unless they are watered down significantly. I find that acrylics tend to stick together so the pages are stuck together. A hassle, sometimes ruining the art work. Sharpies bleed through to the next page. Posca pens are fine. No worries with washi tape. That about sums up what you can do in it. I like the size, and the fact that I can take it with me in my purse. Plus, it fits well in my Midori. Overall, I really love these little books.