Definitions for "Cartellina"
a thin layer of blown glass (usually as thin as 0.2 to 1 millimetre, but occasionally as thick as 10 millimetres) covering the metal leaf in gold and silver tesserae. The cartellina is applied by firing and protects the metal leaf from oxidation. If the cartellina comes loose, a common phenomenon in ancient mosaics, it leads to the loss of the metal leaf and the tessera is discoloured. cartoon for mosaic reproduction