It's a kind of masking tape, only with very cute patterns, made of paper. Not surprisingly, it comes from Japan (like almost eveything cute!).
I saw a picture of a drawing including a strip of washi tape and thought I'd give it a try.
I was lucky to find some. It's not that easy to find interesting craft and drawing materials here.
I have a Lamali sketchbook with very different types of paper in it: recycled, white, orange, black, some kind of fibre, etc. I'm using it exclusively for portraits.
I chose to use the kind of orange-coloured paper instead of the white one. I think it makes it more interesting.
Here are some portraits I did for JKPP, in which I used it.