middle blue – Billy Idyll

What’s the difference between Cobalt Blue and Ultramarine Blue?

January 1, 2024April 6, 2023 by Billy Idyll

Cobalt Blue is a bright middle blue, while Ultramarine Blue is more violet-toned. But Ultramarine Blue also comes in a range of shades, from a Green Shade that is almost identical to Cobalt Blue, to a more violet-toned (and usually more granulating) deep or French shade.

Comparison of DV Cobalt Blue (PB28); WN Ultramarine Blue Green Shade (PB29); DV Ultramarine Blue (PB29); Holbein Ultramarine Deep (PB29); WN Smalt (PV15).

What’s the difference between Phthalo Blue (Green Shade) and Phthalo Blue (Red Shade)?

August 28, 2023August 2, 2022 by Billy Idyll

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?