With the new "Lightfast" series, Derwent has developed pencils that have been tested with 100% lightfastness according to ASTM D6901 - the American standard for lightfast artists' colored pencils. This states that under museum conditions, the work of art can be preserved for up to 100 years without the colors fading. These pens also meet the standard of the Blue Wool Scale with the results being excellent or very good.
You can find out more about the tests, the individual pigments used etc. here:
https://www.derwentart.com/a/341027.
The high value is also reflected in the excellent pigment density. The oil-based leads can be perfectly blended to achieve effects similar to those of oil paintings. In this respect they are very similar to the Prismacolor and also to the Luminance.
