Named for the shadowy edge of a lunar eclipse, Penumbra is a reactive “silvered” cobalt blue, reformulated from one of Paul’s old favorites. Coarse frit is the largest frit size, and has nearly the same granule size as pretzel salt.
Manufacturer’s Working Tips:
Different colors are produced from reduction or oxidation, primarily a wide variety of blues and greens. Reduction can create a luster that you can trap under a clear encasement (Image #4.) However, surface haze doesn’t burn off as easily as amber/purple type glasses.
