Head-to-tail definition
Head-to-tail means the uneven coloring between the beginning and the end of the sample. In case of visual inspection unevenness shall not exceed 4 on the ▇▇▇▇ scale- with a half point allowance for eye subjectivity. In case of instrumental assessment all uneven coloring must be measured by a spectophotometer on the basis of the CMC (2:1) - D65 formula and the resulting delta should not exceed 0.7 (ΔE = 0.7) for all plain fabrics, piece and yarn-dyed alike.