I’m in the process of building my Allegheny & Cumberland & all of the plaster I’m using is plaster cloth. I’ve used joint compound to cover the plaster where needed & then paint on top of that & it holds very well. Since there are mountains everywhere, I’m trying to speed up the project by rather than applying joint compound over the entire terrain, I’m applying painted foil over the plaster without having to paint the plaster then, applying my clump foilage. The foil acts like a second skin & you’re able to apply just like you would plaster cloth, meaning you can cut & stick ( I use clear Dap silicone ) anywhere. All formations start with cardboard grid & now what I’m doing where weight & support won’t be a problem, is just using the painted foil altogether rather than any plaster. Once the clump foilage is on, you’d never know the difference. I don’t ever recall this method being used, so I was wondering if anyone else ever gave this a try.