AMBROTYPES is validvalid

AMBROTYPE, an early photographic technique using black varnish on a glass plate negative [n]

120,691 of 196,601 in NWL2023·also valid in CSW24

AMBROTYPE, a picture taken on a plate of prepared glass, in which the lights are represented in silver, and the shades are produced by a dark background visible through the un-silvered portions of the glass [n]