This glass polishing compound is specifically approved for cleaning the glass cover plates of ambrotypes. Ambrotypes are a specific type of wet collodion photograph made in the 1850s and are very similar to daguerreotypes. It was discussed in a report given at the 11th Triennial ICOM meeting. Opaline is a non-hazardous, odorless white powder designed to be used for polishing optical and scientific glass. It should be mixed with water and applied with a soft cloth, such as our lint-free polishing cloth. 100 gram pot.