What causes little black specks on aluminum that has been primed with polyurethane?
The polyurethane is leaving pinholes, and these are causing a reaction with the silver in the emulsion. The remedy is to give two coats of glossy (not satin or matte) polyurethane. Let the first coat get barely dry, give a second coat and really dry this coat well in warm moving air at least overnight before applying Liquid Light or Ag-Plus. Back to top What’s the best safelight to use with liquid emulsions? With Liquid Light or Ag-Plus, use a light amber (OC) or medium amber (13) safelight, preferably the former as it gives much more light. You can also use a light red (1A) or medium red (1) safelight with Liquid Light. With Liquid Light VC, use a light red (1A) or medium red (1) safelight, preferably the former because it gives much more light. Do not use an amber safelight with Liquid Light VC. What’s the difference between preparing glass and ceramics with glossy polyurethane and the gelatin subbing? Both methods seem to work okay. With the subbing method, the emulsion fuses direct
