I posted this about a year ago but several people have asked to see it again and these are better photos than my original post.
You need to select a nice "slippery" surface to put the tape on so you can remove it easily with no tearing after painting. My favorite surface is a silicone baking sheet. But I think the shiny side of freezer paper taped to a cooking sheet would work well too.
I lay the tape close together and paint them with colorful decorative acrylic paint using a brush. Let dry.
The fun part comes next. Using stencils, stamps or mark making tools add all kinds of delightful fun marks. These are mostly with my handmade stamps and some stencil work using a foam brayer.
Let dry thoroughly.
Peel off gently one at a time and roll up on a large "milk shake" straw. It's a great way to store them until you need them. And the designs all split apart, of course, making interesting and surprising design elements!
I use "paper tape" that you find in the first aid section of drug stores, Dollar Stores or WalMart etc.
Storing them on the straws works very nicely.
I did not invent this…there is a youtube video out on the web somewhere where I saw this done. There are many different ways to make washi tape but so far this is my favorite.