Yeah, i mentioned it is possible to do in blender, but in my experience the process is a bit more fiddly and i wanted to get the process across as simply as possible.
I am printing with ABS and backing it with wood. Use vegetable tanned lather and saturate it with water, being careful not to mark it with your fingernails. Then clamp it down. For larger surface areas, put the stamp under the highest pressure you can. I’m going to try making a 4"x6" stamp here soon and I’m considering putting it in a vice.