Ok I know on Norms plans (which are great) your suppose to use a 1/4\" thick peice of plywood for the mother board but.. what I have found (Cause I have made two seperate proton packs) is that a thicker mother board brings out a better product over all in the end for my first pack I followed norms plans exactly and my back turned out alright but when I did my second pack following norms and my own plans with the THICKER peice of wood a full 1\" thick I found first The wool was easyier to work with, now thats just for the motherboard sawing off the unwanted \"red Zone\" part of the project and also I strongly felt that the end product was both A. more sturdy and B. had a better overall look and feel to it just a suggestion If you want to use the 1/4\" thick board you can It will still turn out fine but I have found and stand by the 1\" thick board.