• The GB-T 250 standard is based on ISO 105-A02.
  • The GB-T 251 standard is based on ISO 105-A03.


The ISO Grey Scales are wholly compliant with GB-T standards.


To order (stock code):

  • ISO 105-A02 Assessing change in colour (766-200)
  • ISO 105-A03 Assessing Staining (766-201)


A PDF version of this FAQ is available for reference.