Okay: this not a poppadom. It's an experiment, and I've no idea if it will work.
I've thinking about a base for my big red fella, and what I would like is some sort of cracked dry earth (like a dried up riverbed). To make it I figured I would need something thin, hard and brittle to break up and glue. I first thought eggshell might work, but gave that up (um... Because we didn't have any in the house). Instead I tried this:
1. Take a sheet of baking paper.
2. Spread fine polyfilla over it with a palette knife.
3. Fold the the paper over and squash it down so it is more or less an even thickness.
4. Unfold and and leave to dry/cure.
5. When dry peel from the paper.
I I now have a rough side (from the lifted paper) and a smooth side (from the side still stuck to the paper as it dried). Hopefully I can break it up and glue down as shards of broken ground. I'll let you know how that turns out - gulp! Still, if it doesn't work I won't be too upset, as it has basically cost nothing and took less than 5 mins to do.