I'm curious what you had because swell touch paper doesn't exactly behave that way, it's thermally activated and the areas you drew on need to be heated up befo

I'm curious what you had because swell touch paper doesn't exactly behave that way, it's thermally activated and the areas you drew on need to be heated up before they will swell. There are sponges that come compressed flat (e.g. soldering iron sponges) and it looks like they sell larger sheets of them for some purpose as well: https://www.dickblick.com/items/hygloss-sponge-ums-pkg-of-4-5-x-7/?clicktracking=true&wmcp=pla&wmcid=items&wmckw=24277-1001&country=us&currency=usd&gQT=1 https://www.dickblick.com/items/hygloss-sponge-ums-pkg-of-4-...