Question: Pls advise about the various light sources (like D60, fluorescent etc) and their specifications for testing the knitted fabric and making lab dips. Asked by Amit Khatuwala.
Light sources by which we check the shade are generally D65(equivalent to day light),TL84(equivalent to Tube light).Apart from those, lots of light sources (TL83,ULTRA VIOLET,COOL WHITE,U30 etc) are available in the market. As per buyer requirement we have to check the shade in that specified light.
For checking the color fastness properties we generally use Xenon arc which is very similar to day light. Apart from that we use MBTL & carbon arc. Fading unit is AFU. We generally check by 5 AFU (approx. 4 hour fading),10 AFU (approx. 8 hours), 20 AFU (Approx. 16 hours). Every buyer specify their light source, time & requirement.
Before production starts every mills dye a swatch in their lab to fix color recipe. When that matches with the actual swatch they start their production. Please note that shade should be matched in buyer specified light. That lab produced swatch is being called as lab dip.
Answer by Saumyadip Santra
Related post: What is lab dips