Colour Fastness to Light Setting It Correctly on a Tech Pack
Colour Fastness to Light should be written into the tech pack with a value, a tolerance and a method. This removes ambiguity from quotations.
Definition to agree
resistance to fading under light. Working figures for Colour Fastness to Light normally sit around grade 4-6 by end use in mainstream production. Note ISO 105-B02 xenon arc on the tech pack so nobody tests against an older revision.
Target value
Open the specification at grade 4-6 by end use, adjusted to the end use. Record elastane content alongside Colour Fastness to Light, because blends shift the measured value. A result outside grade 4-6 by end use usually points to process drift rather than to the fibre itself.
Method line
Always pair the target with ISO 105-B02 xenon arc so the mill and the laboratory test the same way. Keeping reference values for Colour Fastness to Light lets suppliers quote without extra sampling rounds. Ask for conditioning details together with ISO 105-B02 xenon arc, since both affect the reading.
Tolerance line
State plus or minus limits to keep production realistic while protecting the requirement. Working figures for Colour Fastness to Light normally sit around grade 4-6 by end use in mainstream production. Note ISO 105-B02 xenon arc on the tech pack so nobody tests against an older revision.
Approval step
Approve the result on pre-production bulk rather than on development fabric only. Record elastane content alongside Colour Fastness to Light, because blends shift the measured value. A result outside grade 4-6 by end use usually points to process drift rather than to the fibre itself.
