Derwent Lightfast Pencils have been formulated to be 100% lightfast. The revolutionary core is resistant to prolonged colour change ensuring artwork will not fade for 100 years under museum conditions.Tested under the harshest conditions to internationally recognised standards, this premium range of oil-based pencils offers an incredible range of colours not seen in other lightfast collections.100% lightfast, all colours are superior quality and comply with ASTM D6901 and Blue Wool Scale ISO 105Revolutionary oil-based core creates a buttery, velvety texture allowing colours to mix and blendRich, vibrant colours that deliver a rapid and opaque laydownColours can be mixed on the page to create a paint-like effectStrong point for detailed drawing and layering techniques