Cerulean Blue - A comparison
Feb. 5th, 2016 08:57 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
tatyanavf1Cerulean Blue - A comparison
http://lispencie.tumblr.com/post/138733231669/cerulean-blue-a-comparisonWatercolour is a tricky business. I have always seen it as the ‘chess’ of painting; You really need to think ahead to succeed. Besides this, watercolour paint behaves erratically. This creates beautiful effects with the right surface and the right paint, but it means that any direct comparison of paint quality is highly debatable. The appearance of every brush stroke can differ with the artist, brush, paper, medium, dilution, tilt, drying time and quality of paint. There are too many factors involved for this to ever be scientific.
Nonetheless I have attempted to compare Cerulean Blue by Sennelier (Artists’ quality paint) with Cerulean Blue (Hue) by Cotman (Student grade paint)
Sennelier Cerulean Blue Retails for around £10 per 10ml tube
Cotman Cerulean Blue (Hue) retails for around £2.50 per 8ml tube
I focused on Cerulean Blue as it featured in a recent online watercolour class I underwent. This colour was used for every sky, so I got through it quickly. As a series 4 colour it is expensive, especially when being used for practice. So I set out to see if Cotman was a good substitute.
I mixed the blue with the other primaries to see how it behaved. For Cotman I chose Raw Sienna and Cadmium Red Pale, because it is one of the reds that comes in the Cotman pocket box. For Sennelier I chose to mix with Raw Sienna and Scarlet Lacquer, as this is a bright, pale red like Cad red pale. Although slightly cooler.
These were both tested on the same sheet of watercolour paper, and with the same brush. Straight away the Cotman appears to be more dye-like rather than pigmented. There is little, if any, graining. Disappointing as this is one of the main features of Cerulean Blue as a watercolour. Next I mixed some secondaries. These are a little skewed as I didn’t pay precise attention to the ratios of paint used.
The cooler red used in the Sennelier set has resulted in predictably cooler secondaries. The Cotman, while not at all unpleasant to use, results in flatter washes. The purple mixed from Sennelier shows the Blue and red clearly as separate pigments, ready to mix in the mind’s eye.
A closer look at the blues and purples; In order of Cotman Cerulean, Sennelier Cerulean, Cotman mixture, Sennelier mixture
Finally, I mixed some greys;
These greys are very diluted, so the difference in grain virtually disappears. The Cotman greys seem flatter in colour than the Sennelier. Again the solid pigments in the higher quality mix sit side by side, rather than blending smoothly.
Here are the paints used to make some skies;
Cotman
Sennelier;
Cotman is usable but it won’t behave as true Cerulean Blue when used in washes. Maybe the addition of granulation medium and some Alizarin crimson would bring it up to point. Although, how effective granulation medium is I have yet to discover. Please let me know if you have tried it!
Signing off with my original (& messy) test sheet!
