Variable Contrast Paper
Paper carrying two emulsions of different contrast and colour sensitivity, whose grade is set by the colour of the enlarging light.
Measured in
grade equivalent
In depth
A yellow-green filtration exposes the low-contrast emulsion and a magenta one the high-contrast emulsion, so a single box of paper covers the whole grade range. Beyond convenience, this permits split-grade printing, where different parts of one print receive different contrasts — something graded paper cannot do at all.
Examples in practice
Dialling in 40 magenta on the enlarger head raises the effective grade from about 2 to about 3½.