Blending
Dyed fibre loses more in blowroom and carding than white does. Gross both up at the same rate and the shade drifts light every time.
— kg
Weighed out at the mixing bale, before process loss
Where the achievable share misses the target, move the ratio into the blowroom mixing instead of the creel — chasing shade with sliver counts alone quantises it too coarsely at low percentages.
Melange Yarn Fibre Blending Ratio Calculator — free, with the formula and a worked example, at Textile School.