Quote Originally Posted by Supine View Post
... The main struggle, I think, will be creating another one when they inevitably go too far to one direction and I have to match the borders.
Glue, or tape, the next piece of paper firmly to the edge you're expanding, then fold and crumple more gently? Or fix it digitally if you don't need it as a 3d object?

For materials, I'd probably try painted aluminum foil first for durability and minute fixing of details, but parchment paper or waxed paper might work too and they're both reasonably water resistant. Tracing paper's kinda interesting as well; it has a wrinkly shrivel-ish tendency when it gets wet. If you go with something that can hold pigment as well as water, then once you find your lakes, or maybe better... if you use an eye-dropper and selectively drop water into the highest valleys without hitting the slopes too much, add some color to the water and it'll stain your river paths and water bodies for you. Watch you don't do any of this over something that's not washable, though, and mind that your landscape is stable enough that it won't tip over when you don't want it to.