When using our Blue Wool Standard 6 to test to ISO 105-B06 (2020): Textiles, tests for colour fastness: Colour fastness and ageing to artificial light at high temperatures. It has been determined by the manufacturer DEK, that the blue wool standards from batch 2230 KLS III and 2230 KSL V fade faster than the previous batches 2230 DL – which is considered the de facto global standard.

Now the German Fastness Committee (DEK), published a correction factor for the latest batches of ISO Blue Wool No. 6 for hot light fastness testing. The correction factor was established by the Saxon Textile Research Institute (STFI) by directly testing new batches 2230 KSL III and 2230 KSL V along with previous batch 2230 DL next to each other in a Xenotest Beta with Xenochrome 320 filter and ISO 105-B06 conditions 3), until a color change of ΔE* = 4.3 ± 0.3 was achieve on the 2230 DL control specimen.

For the new batches the following correction factors have been determined:

• 1.24 for 2230 KSL III
• 1.27 for 2230 KSL V

This means that the target values for one exposure period of ISO 105-B06 Condition 3) for the new batches are:

• 2230 KSL III: ΔE* = 5.3 ± 0.3
• 2230 KSL V: ΔE* = 5.4 ± 0.3

With these target values the same radiant exposure, and the same exposure duration will be achieved as for the older DL batches of Blue Wool No. 6.

All of the SDL Atlas blue wool 6 come from batch 2230 KSL III, and this correction can be applied. The DEK batch number will be listed on the SDL Atlas Certificate of conformity.