2 different recipes. Brands sell different pigment mixtures under this name, so they won't all look or mix alike. Compare the pigments below.
Who makes it
PY65 Arylide Yellow RN1
- Grumbacher Pre-Tested Artists' Oil No. P060
PY14 Diarylide Yellow1
- PY14LF II TransparentSeries 240 ml tube · 110 ml tube · 300 ml tube · 1000 ml tin · 4000 ml tinAbout Langridge
Sizes are the ones each line is sold in; marks a size only some colors come in. Check the store for a particular color.