So something that you need for a Necromunda Ash Wastes (N:AW) game is in fact "ash wastes", that is a playing surface. Your usual green felt or shattered future city is not really applicable. N:AW has effectively two game scales, one which is the usual Necromunda scale skirmish, which you play on a 3x3 foot or 4x4 foot board, and "rolling roads" where there is some sort of vehicular chase/heist/etc. which needs a 6x4 foot or two boards that you switch to represent the road passing by. The boxed set came with a rather nice 3x3 foot printed paper mat, which has a day and night side, but it is glossy and already showing a bit of wear at the folds. So the idea came to make a new game mat to represent this surface, and more to make it from a new technique. [who would be smart enough to use a tried and true technique?]
Googling around for various ash wastes mats, I somehow came across this video from Black Magic Craft. He has a few more videos that use this same technique to make roads and rivers, which might have been where I found it the first time.
I really liked how it seemed heavy and dense compared to caulked canvas, and the idea of using rollers and other things to mark the caulk seemed like a good one. So after some research, I found a similar runner from Lowes (the same product as the video is not sold at Home Depot in the US), bought some caulk, and got to work.
So to learn how to make one, continue after the jump.