I had a bunch of Zentangles that were either unfinished, or I wasn't happy with how they turned out. So, since of course I'm unable to throw anything away, I decided to chop them up and make some ATCs out of them. It was a good way to use them up, and I'd like to play around more with different tiling options.
The blue base is card stock, so it was pretty solid, but the pink is a weird paper/plastic wrapping paper, so it was flimsy. I added more Zentangle scraps to the back to make it a bit stiffer: