The very-expensive, highly-toxic Vermilion red was replaced by the lesser expensive and less toxic Cadmium reds in artist’s palettes in the nineteenth century. Less toxic and less expensive was less than perfect so the search for the perfect red continued. Eventually, chemists came up with a fairly good substitution for Vermilion and Cadmium. Naphthol Red was born in a chemistry lab as a derivative of coal tar.
Just Paint on the Golden Paints website describes Naphthol Red as, “bright, opaque, fire engine red.” Gamblin’s website says Naphthol Red is a, “modern organic, warm red that closely matches Cadmium Red Medium,” though Naphthol Red “makes more intense tints” and is “more transparent.” Gamblin also reports Naphthol Red is “excellent for high key painting.” AArbor Colorants recommends Naphthol Red for printing inks and gives it an excellent light fastness rating. Some sources report Naphthol Red as fading in tints. Confirmation of this claim was not confirmable so tests may be in order.
Naphthol Red does not have the toxic properties of Vermilion and the Cadmiums and is considerably less expensive. The Material Safety Data Sheets give Naphthol Red a very low toxicity rating. The MSDS says Naphthol Red may cause some mild skin irritation, nausea if consumed, or some respiratory irritation if inhaled. Contact in large amounts could be more toxic.
If in need of a bright intense fire engine red, Naphthol Red may fit the bill, especially if you don’t want to shell out a lot of money. Just don’t have the Naphthol Red for dinner or add it to body lotion. It’s probably not a good idea to set any dried pigment around a fan either. Otherwise, Naphthol red can be a palette staple as a strong red without fear of damage to health or wallet.
My preferred red for botanical painting is Naphthol Red or its sister: Windsor Red. Thinning is required to achieve the transparency of botanical painting. No other red comes close to the intensity of Naphthol Red or Windsor Red so use with extra water and enjoy the intensity!