In a mill, shade means the color target a grade must hit, defined by L*a*b* values, a physical master sample or both. Every white has a shade, from blue-white office paper to natural book stock, and shade is set by furnish, dyes, optical brightener and filler together. Shade control means trimming dye pumps to keep readings inside the tolerance box across reels, both sides and grade changes.
Shade is walking toward red on the back half of the reel, check the dye flow before the next turn-up.
Also heard as
- color
Related terms
Off shade
Describes paper whose color has drifted outside the tolerance of its approved standard.
CIELAB
Color space describing a color by lightness L* plus a* for red-green and b* for yellow-blue.
Shading dye
Small dose of blue or violet dye used to cancel the yellow cast of a white sheet and steer its tint.
Chasing shade
Making repeated dye or brightener adjustments to pull the paper's color back onto target after an upset.
Delta E
Single number for the total color difference between a sample and its target, usually in CIELAB units.