Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

This may be an anti tarnish compound. Many anti tarnish compounds contain
amines that form very strong bonds to copper and often act as a base for
adhering other materials. They are commonly used in photoresist
compositions to enhance adhesion. Toner may (note I said may) actually
stick better to an amine treated surface. Amines are readily removed in
acidic etching systems so they shouldn't cause any problems in later
processing steps.