I used a 1/4" polished plate and just lay it on my bench. Go to Lowes Aircraft Supply or Big Orange and buy 2 24x24 carpet tiles. They are rubber backed and about 1/4" thick (buy 3 or 4 if you want a larger area). The rivet plate stays put and you can move it wherever it is needed. I find this much more flexible than embedding it and it takes less time to build and more time to bang rivets.![]()