ZU-130 is a "U" border frame with a 1/8" or 3mm face and a 1/8" or 3mm channel that accepts most standard art glasses. This low cost zinc frame provide some added strength to your stained glass panels, and creates a clean, finished look to your panels. The zinc alloy also resists oxidation, making for easier soldering and permitting a longer tarnish-free shelf life and will readily accept a black patina.