I know the Cometic gaskets are like a rubber coated copper if that helps.The Vesrah brand gaskets are probably the closest to stock thicknesses.Vito's has some pretty good gaskets available too.They offer many diff thicknesses for special needs.We use Vito's for a big reed motor we have,because it uses a .060 base gasket.I have never used any of the other brands.I have always used stock,cometic,or vesrah.