Opalotype or opaltype is an early technique of photography. Opalotypes were printed on sheets of opaque, translucent white glass; early opalotypes were sometimes hand-tinted with colors to enhance their effect. The effect of opalotype has been compared `to watercolor or even pastel in its softer coloring and tender mood.` `Opalotype portraits........
photograph taken on a milky opal glass plate
• (n.) A picture taken on `milky` glass.
O·pal'o·type noun [ Opal + -type .] (Photog.) A picture taken on 'milky' glass.