I've been messing around with the idea of using masking tape to create layers. Sometimes it turns out well and other times it's a disaster. What usually ends up happening is the tape sticks to the edge of the paper and tears off a layer of the painting. I was very careful to make sure that didn't happen this time.
I started from the middle and worked my way out. At first, I was very patient and waited for each layer to dry before taking the tape off. When I saw that it was working and that I was liking the effect, I grew more excited and thus, more impatient. So, I got out my hair dryer and started blowing each layer dry. The result was paint bleeding under the tape-- which I kind of like in this case. I think this would be awesome on a full sheet of watercolor paper-- if I can get it to work!