A well-appointed palette for the landscape painter will allow you to mix just about any color you need. My expanded primaries palette is one such palette. An essential color on that palette is phthalo blue (prounounced: tha-low) , that rich and delicious shade of blue that is able to produce the brilliant “sky blue” color we are all so familiar with.
Side by side, ultramarine blue (left) is very different than phthalo blue (right). Ultramarine is a “cool” blue, while phthalo is often identified as “warm” because of its hinting toward the green end of the spectrum. Although ultramarine is the most universally accepted pigment on the landscape painter’s palette, it cannot produce the distinct hue phthalo can, even when mixed with other colors. (See my answer to Kate’s question in the comments section below, about designations for phthalo and ultramarine.)
The problem with phthalo is that it is so intense and strong, that even the smallest amount can overpower any mixture. If you were to replace ultramarine with phthalo for most of your blue mixes, your painting would take on a strange, acidic blue-green pall.
So, instead of traditional phthalo blue, I turn to two special pigments: “Mediterranean Blue” from Daniel Smith and “Azure Blue” from Sennelier. Mediterranean blue is simply phthalo and white together. Azure blue is phthalo and a little phthalo green. Straight from the tube, both of these pigments look nearly identical to phthalo when it’s been lightened with white. These two pigments are still potent, but much less so than regular phthalo, so they have less chance of overpowering your mixtures.
You can also simulate these two pigments by simply premixing phthalo with some white. In fact, before I discovered Mediterranean Blue and Azure Blue, I always added white to phthalo on my palette. Lightening in this way not only makes it easier to handle, it also distinguishes it from ultramarine on the palette, because out of the tube, they look very similar.
Another alternative to phthalo is manganese blue hue. Straight from the tube, manganese is about the same mid-value as Mediterranean and Azure blues. However, it is not as potent as Mediterranean, Azure, or phthalo. This means that you can use it without concern that it will overpower your mixtures.
This post yielded many helpful comments from readers.
- There are two other phthalo-like pigments from Holbein, Hydrangea Blue and Caribbean Blue..
- Cerulean blue (a pigment I did not mention) is also in the same warm blue family as phthalo.
- About Gamblin’s 1980 Phthalo (their line of student-grade paint), Carol notes, “Because it has less pigment and more filler, the color is not as intense as regular phthalo.”
- See Tom Hoffmann‘s comments below on how he manages phthalo by mixing it with other colors.
See full comments below.