Digital BW, The Print

I should also mention I was talking about RC color prints only when I said the RC base problem is largely cracking of the PE layer. For RC B&W prints, those free-radicals also generate peroxides which then attack the silver particles in RC B&W prints. Selenium toning prevents this problem but few RC B&W prints are ever chemically toned because the additional toning step is somewhat at odds with the convenience of rapid processing. Most print processors aren't set up to add an additional toning step. It has to be done by hand in a tray.

When the silver particles are attacked by the peroxides you see all sorts of weird tarnishing and "halo" effects around high to low density areas in the BW RC prints. Not very pretty unless you like abstract art!

Mark
http://www.aardenburg-imaging.com