Phthalocyanine blue (PB15) is an incredibly intense, staining, transparent, non-granulating, lightfast pigment that comes in two versions:
- Phthalo Blue Green Shade (PB15:3)
- Phthalo Blue Red Shade (PB15:6 or PB15:1)
(I’ll call them GS and RS in this post.)
What’s the difference, and which should you choose?