Caran d'Ache 20 Luminance 6901 Coloured Pencils Set Artists ProfessionalDescriptionSpecificationsShipping Luminance 6901 is the colour pencil which combines the best possible lightfastness with the smoothness of a permanent lead made with wax. In accordance with the international ASTM D 6901 standard (which certifies the lightfastness of colours on a scale from LFI to LFV), Luminance 6901 offers to the demands of the most exacting creative professionals the guarantee that their works will stand the test of time for up to