Sampler Pack This pack includes 1, 12" X 12" sheet of each of the following, for a total of 4 sheets: 1 mil (.001" thick) 1.4 mil (.0014" thick) 3 mil (.003" thick) 5 mil (.005" thick)/ 36 gauge. Premium Copper Alloy 110 (99.9% pure copper) Smooth Commercial Finish/Annealed (Dead Soft).