Coating materialusedin etching, intin-leadcoating,during the applicationof solder,andin wave solderingwith the purpose of protectingcomponents of the circuit boardfrom oxidation by contact with the etching solution orthesolder.There are different kinds of resist, such as photofoil (dry film resist orathree-layeredfoil consisting of asupport film,photosensitiveplastic and aprotective film), organicresists made of commercially availableplastics (e.g. polyamide, polyethylene, or urethane),or metallicmasksact.In metallicmasks,tin-leadcoatingis mainly used, but gold or rhodium resistsare also manufactured.These are known assolder resists.