Blue toning kit

Description

Iron-blue toning of a silver print: silver is replaced by Prussian blue and a black-and-white photograph turns blue — from a barely perceptible cool cast to a saturated cobalt.

What you control

Depth is set by time: pull it early for a cool neutral print, leave it longer for a saturated blue. The process is reversible, so overdoing it is not fatal — a mildly alkaline bath takes it back.

What to watch

Blue toning raises density and can close up shadow detail, so print a little lighter than usual for it. On warm-tone papers the result reads greenish rather than a clean blue.

Questions and answers

Is a toned print permanent?

Prussian blue is sensitive to alkali — do not store toned prints in alkaline mounts or carbonate-buffered albums.