Fig. 6From: Prestige markers in art: subtle stratagems in material selection for fifteenth-century stained-glass windowsInclusions on interior side of the glass surface suggesting the Ca-rich blue glass pieces were produced with the cylinder forming technique. As examples, we picture the interior side of a piece 7 from panel AV.1164 in reflective light and b piece 10 from panel AV.1165 in transmitted lightBack to article page