panel 20 (condition of internal surface):
Glass: less deteriorated than external face. Departure of the surface of the glass on
Paint: ancient painting with thick lines and wash drawing, brown-red and black painting
Lead: good condition
Putty: dry and waterproof
Consolidant: not visible except after a light cleaning (cotton swab moistened in water),
no sign of alteration
Deposits: white (brownish) deposit on most of the pieces (distemper? putty residue?).
They often dissimulate glass corrosion.
Bonding: silicone glue retouched with a cold brown painting when necessary, no sign