Cerulean blue is a popular choice for watercolor palettes, including my own. I use very few granulating colors but Cerulean is one that has a permanent spot in my palette.
Most tubes of Cerulean watercolor currently on the market are formulated from either PB35 or PB36.* Both of these blue pigments are oxidized from cobalt—cobalt tin oxide (PB35) or cobalt chromium oxide (PB36)—so you may occasionally find watercolors using "cerulean" pigments labeled as Cobalt Chromium, Cobalt Azure, Cerulean Oxide, Cobalt Light, etc.
Cerulean pigments are rather opaque and granulating. Because of this, I find the popular phrase “cerulean skies” a bit funny because it seems contrary to paint an opaque, granular sky. However, Cerulean is actually one of my favorite colors to use in a sky like in the swan painting featured above. Cerulean's soft appearance and satiny textures can create lovely color and depth in elements like skies and shadows—at least when diluted and used sparingly.
Because this is not a pigment that tends to looks great in masstone! Many Cerulean watercolors can appear rather dull or chalky, especially when used alone. However, when partnered in a painting with other blues like standard Cobalt (PB28) or Indanthrone (PB60) or when charged with a bold color like Quin Violet or Rose (PV19), I think Cerulean lends a nice contrast and softening feature that I’ve yet to find in any other blue.
*To learn more about what these letters and numbers mean, see my post here.
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Examples of Cerulean Blue Watercolors
Below are swatches of various brands of Cerulean Blue watercolor. Because of scanning and monitor discrepancies, these swatches won't be 100-percent accurate but can give you a fair idea of how these paints look on a page.
These swatches were completed on Hahnemühle Cézanne 140#/300g cold-pressed paper. Though all of these Ceruleans appear very similar in mass tone, their performance is not the same. Below the swatches, I share my personal opinions about each brand's Cerulean.
Paints are listed below in alphabetical order according to brand. Click on the title to see current pricing and/or more information. For tips on saving money when buying watercolors, see this article.
American Journey Cerulean Blue (PB36)
A silky smooth Cerulean with light, easy-to-manage granulation and solid color. This is the Cerulean currently in my palette, and you can read my full review of American Journey paints here.
Daniel Smith Cerulean Blue Chromium (PB36)
I've owned this color for two years but have yet to discover why it has a mass following. It's a rather dark, smoky Cerulean with massive granulation that's difficult to control. I actually like it in masstone but that's not how I use Cerulean. However, if you like this one's color and surprisingly strong granulation, I applaud your choice.
Da Vinci Cerulean Blue (PB36)
My other top pick. A solid performer with beautifully light granulation. Very similar to American Journey but Da Vinci contains a high amount of gum arabic so I think this one has slightly more movement on a page. You can read my full review of this brand here.
Holbein Cerulean Blue (PB35)
This is a beautiful color and was one of my first Cerulean blues. It has light to moderate granulation and dilutes well, but the color often acts a bit finicky and streaky. Because of this, I've since moved on but if you're partial to a PB35, Holbein (Hole-bean or Hole-byne depending on whether or not you're German and correct, which I'm often not) is a nice one.
M Graham Cerulean Blue (PB36)
This is the most saturated Cerulean of the bunch and was the pick for my palette until I grew tired of finding leaky messes every time I opened my sketching pack. It is gorgeous in masstone, strikingly bold, and has little granulation. However, it lacks the luminosity of other brands plus it can occasionally appear glittery. Yes really. See the video for more details.
Rembrandt Cerulean Blue (PB36)
The color is good and granulation is lovely, but Rembrandt is explosive on a page. I recommend it only for artists who could care less about control and/or prefer a paint that has a mind of its own. You can read my full review of this brand here.
Schmincke Cobalt Azure (PB35)
This is a beautiful Cerulean that paints out light and airy. It has a strong amount of granulation but is rather transparent so it's not overpowering. It's a solid performer but can be an expensive option in the States. (If you're interested in Schmincke, check Jackson's Art via the link above. They offer affordable or free international shipping and their prices on EU brands are often unbeatable.)
Cerulean vs Cerulean Hue
When shopping for a tube of Cerulean watercolor, you may notice paint labeled “Cerulean Blue Hue.” Never, ever go by a paint name—there are no standards for those—but instead look for the letters and numbers on the back. This will tell you what you’re really getting. Most Cerulean hues are some variation of Phthalo Blue (PB15) mixed with white, probably either PW4 or PW6.
If you’re not partial to the granulation in cobalt cerulean pigments, Cerulean Blue Hue is a fine choice for a palette. It will be more staining but also more vibrant and possibly more transparent. Though you can mix it yourself, many watercolor artists prefer the ease of this convenience shade straight from the tube.
The video below has two examples of Cerulean Blue Hue paints. Because it contains Phthalo Blue, this color is brighter and clearer than standard Cerulean. Because any "hue" is a mixture, different brands will vary widely so I think it’s worth trying a few to see which blend you like best.
Mixing with Cerulean Blue
Because Cerulean can be rather flat and granular and has a weak tinting strength, it’s not the best mixer in the world. Cerulean often likes to separate out of mixes and can also produce a weird halo effect. Unfortunately, these effects won't show themselves until the paint is dry so you won't know the final outcome until it's too late.
A perfect example of how Cerulean can misbehave in mixes is the Cerulean/Pyrrol combo in the photo. The granulating effect is rather pretty but unpredictable, and you can also can see an interesting halo around the edges. Unless you like this look, it's best to experiment with mixes before painting.
Because of Cerulean's finicky nature in a crowd, it's not a major mixer in my palette. Instead of mixing, I prefer to charge this paint with various colors directly on the page. Regardless, there are a few Cerulean combos that I really love, so I’ll share these along with a few extra mixes below.
The Cerulean I used for mixing is American Journey's PB36, but a brand's nuances usually aren't enough to sway mixes so all of these Ceruleans will produce nearly identical colors. Just be aware that the more a Cerulean granulates, the more it may separate and halo in mixes.
Note: I show off a few more Cerulean mixes in the video tutorial.
Video Comparison: Cerulean Blue Watercolors
View these watercolor brands in action and see a few of my favorite Cerulean mixes in the video below. I hope this helps you pick the best Cerulean blue for you, and happy painting!