Testing & Quality Control

Grey Scale Staining Rating Interpreter

Grey scale grades are not linear in Delta E. Grade 4 to 3 spans twice the difference that 5 to 4 does.

Measurement Adjacent fabric
dE
Specification Buyer minimum
grade

Grey Scale Grade

— grade

Grade 5 is no staining, grade 1 is severe

Compliance

Shortfall Against Minimum
— grade
Delta E at the Minimum Grade
— dE
Delta E Margin
— dE
Staining as Share of Grade 1
— %

Instrumental grading must be correlated against physical grey scales under a controlled light booth before it is accepted contractually.

Grey Scale Staining Rating Interpreter — free, with the formula and a worked example, at Textile School.