The shim is very simple, and simple to make. I use a used DE blade and cut the cutting edges off of it. With a sharp pair of scissors. Place the shim on the cap after you have placed your favorite blade, in other words, underneath your shaving blade so as to lift it up and away from the baseplate, creating a larger gap.This is interesting. What is this shim like?
I plan to try R41 with a Yagi Beast cap. Some brothers here write it is a good combination. SLOC cap is also used but can't find such.