One of the most common questions we get about our neon line of oil paints is about lightfastness. Lightfastness refers to a pigment's ability to resist fading when exposed to ultraviolet light. Oil paints are typically rated by ASTM (American Society for Testing and Materials) standards for each particular pigment in the paint. For more common pigments one can find the lightfastness rating listed as:
I: Excellent; II: Very Good; III: Fair; IV: Poor; V: Very Poor
All pigments will fade over time due to the effects light, heat, and humidity. In order to be considered "archival" pigments need to be rated either ASTM I or II. Fluorescent pigments do not have a standardized lightfastness rating because each manufacturer has patented and secret processes that they use to produce their pigments. We selected our pigment supplier based on the quality of their pigments.
We can, however, get an idea of the lightfastness of our neon colors by conducting blue wool testing. To do this we painted our six original neon colors on a white piece of paper and exposed only half to direct sunlight. We also exposed half of a blue wool card directly underneath the painted colors. Over the past year and a half we have been tracking the fading of the blue wool and checking to see if there is any observable fading of the paints.
So what have we found? As you can see below, the blue wool test strip shows visible fading on 6 of the blue strips. The neons exposed to the same amount of daylight show no fading or color-shifting. This means that they are at a minimum the equivalent of an ASTM III - Fair lightfastness (Impermanent) "The pigment will remain unchanged for 15 to 50 years with proper mounting and display. (May be satisfactory when used full strength or with extra protection from exposure to light.)"
We will continue to monitor our testing to see if the paints show any changes once the 7th blue wool test strip begins to fade more noticeably.
Blue Wool Test Strip
Gapka Fluorescent Neon Oil Paints
Closeup of Gapka Fluorescent Neon Oil Paints
If you are interested in the chemistry and history of UV fluorescent paints you can read more at: https://journals.openedition.org/ceroart/1659.
* These tests are reported for informational purposes only and do not represent a guarantee of lightfastnest.