Black Patina is a chemical that turns solder black - use black back foil with this otherwise you will see copper through your glass (unless it is opaque). Also known as 'Black-It'
Simply brush onto your solder after cleaning thoroughly with soapy water to remove any flux residue. The patina reacts with the tin content in the solder, changing its colour. Best applied with a flux/patina brush.
Safety Data available upon request.
This item cannot be shipped air.