2 different recipes. Brands sell different pigment mixtures under this name, so they won't all look or mix alike. Compare the pigments below; the most common is PR112 Naphthol Red AS-D.
Who makes it
PR112 Naphthol Red AS-D5
- M. Graham Artists' Oil Color No. 120
- PR112LF II Semi-transparentSeries 340 ml tube · 150 ml tube · 300 ml cartridge · 500 ml tin · 1000 ml tin* · 4000 ml tin*About Art Spectrum
- PR112LF I Semi-opaqueSeries 340 ml tube · 110 ml tube · 300 ml tube · 1000 ml tin · 4000 ml tinAbout Langridge
PR188 Naphthol Red HF3S1
- PR188LF I Semi-opaqueSeries 340 ml tube · 60 ml tube* · 225 ml tube · 1000 ml can*About Michael Harding
Sizes are the ones each line is sold in; marks a size only some colors come in. Check the store for a particular color.