The 500 line is a premium semi-gloss alkyd enamel coating that is formulated for high traffic, hard service areas where excellent washability and durability are demanded. This tough, durable product is easy to apply, has outstanding flow and leveling properties, and excellent sheen uniformity. Dirt, stubborn ink spots, pencil, crayon, or finger smears all wash off easily without marring the finish of this high hiding coating. While all interior alkyd-based products may yellow in white and pastel colors that do not receive ultraviolet light, this product contains a unique resin that is superior to most traditional alkyd resins. This product is also sold with a non-yellowing additive to further improve the non-yellowing performance. Yellowing is an inherent characteristic of all alkyd resins. To avoid yellowing from occurring entirely, a water-based product is recommended.