Following extensive testing, we can confirm that all 100 colours in the Lightfast range are 100% lightfast, meaning they are lightfast for up to 100 years (under museum conditions).
Derwent Lightfast features an oil-based, opaque and vibrant coloured core, that is 100% lightfast. You can get smooth, velvety laydown of colour and when mixed with oil mediums, the pencil colour can behave more like an oil paint.
Lightfastness refers to the chemical stability of a pigment under long exposure to light. The Derwent Lightfast range has been tested according to the ASTM D6901 standard, which states that pencils with a rating of LFI and LFII are fully lightfast.