Answer by
LeheckaG (1826)
"Patina" refers to surface-films, usually on metals or wood, due to:
exposure/weathering, and/or polishing.
Either adding metallic-salts to glass:
quartz/silica-sand, CaO/calcium-oxide/lime, MgO/Magnesium-oxide, & Al2O3/Aluminum-oxide
during during manufacturer,
or applying paint(s) to glass, and then firing/kilning
produces "stained glass".
Different paints/surface-treatments result in different "patinas".
Working glass-surfaces when hot/soft yields different-textures.