Studio Pro 7/32" Silver Backed Foil is a 1.0 mil copper foil and is sold in 36 yard roll in a unique “Easy Pull” plastic dispenser makes for trouble-free application and kink-free storage. This 1.0 mil copper foil is is sold in 36 yard roll. When To Use: Silver backed copper foil has an reverse silver coating to help camouflage the appearance of the foil when used on clear, wispy, non-opalescent glass and mirror when it is desired to leave the solder its natural silver color.