Sunburst Symbol PanPastel Asterisks ASTM Rating ASTM Rating Definition*
I EXCELLENT At least 100 years lightfast under museum conditions
II VERY GOOD 25 - 100 years lightfast under museum conditions
III FAIR 10 - 25 years lightfast under museum conditions
* There is no official ASTM lightfastness standard for pastels, therefore we apply the standard for Colored Pencils which is the closest standard available.