Paint Pigments: Naphthol Red (PR170)

A profile of naphthol red paint pigment, including its characteristics.

PR170 Napthol Red Medium pigment
Paint Pigment: Napthol Red Medium PR170. Photo © 2009 Marion Boddy-Evans. Licensed to About.com, Inc.

Characteristics: Naphthol red is an intense, mid- to deep red, heading towards rose-red when thin.

Common Names: Naphthol red medium, naphthol crimson, permanent red, permanent crimson.

Color Index Name: PR170
(Color Index Explained)

Color Index Number: 12475

Pigment Origin: A synthetic red.

Used for Painting Since: 1920s.

Opacity/Transparency: Transparent/Semi-transparent.
(Opacity Explained)

Tinting Ability: Good.


(Tinting explained)

Lightfastness Rating: ASTM II.
(Lightfastness explained)

Oil Paint Drying Speed: Slow.

Specific Notes:

  • Often used instead of cadmium red (which is a toxic pigment)
  • Check the lightfastness rating on the tube as paints sold as naphthol red are not lightfast.