James Heal Blue Wools are made in Germany and originate from DEK – The German Colour Fastness Commission. DEK hold the global master standards.


Every batch of Blue Wools 1-7 is rigorously tested for conformance against ISO 105 - B08.


These tests are:

  • Instrumented assessment of evenness of the dye
  • Instrumented and visual assessment of the fading characteristics


Blue Wool 8 is not suitable to be tested in this way as the time taken to fade to a grade 3 and 4 would be too great and not time effective.


A more efficient method for Blue Wool 8 is currently being devised.


A PDF version of this FAQ is available for reference.