Lightfast - oil-based pencils with high levels of light resistance, to resist fading for up to 100 years in museum conditions.
With a smooth oil-based core that creates vibrant colours on the page, Derwent Lightfast uses the finest quality pigments to ensure your work won't fade. They've been tested extensively, and should show no fading for up to 100 years under museum conditions. All colours comply with standards ASTM D6901 and Blue Wool Scale ISO 105.
For the best and most permanent results, Derwent recommend:
Using high quality pH-neutral heavy-weight paper.
Creating strong even layers - avoid being too rough and damaging the paper.
Avoid direct sunlight when hanging your work.
Hanging behind glass is best, especially glass with UV-absorbant coating.
Avoid mixing with other products - this may reduce the level of lightfastness.
Mix colours by layering one colour over another. Dark colours applied firmly will make an opaque mark, covering up the lower layers. Applying more gently will allow colours to mix, blending from one to another.