Thursday, August 19, 2010
Evaluation of Alizarin and Substitutes
Alizarin Crimson replaced the Madders which were fugitive (not very permanent). Alizarin is better than the old pigments but new pigments offer better performance in terms of permanence. Some paint manufacturers have stopped making Alizarin in favour of the substitutes while other manufacturers off both. So lets see if a change is warranted.
Here is a canvas patch with Alizarin, Permanent Alizarin, and Quin Red placed across the top. The pigment swatches were placed thin and then titanium white mixed in and pulled down in order to see the colour. Then Viridian, Ultramarine, Cad Yellow Deep, Yellow Ochre, and Transparent Red Oxide were placed vertically on the left in thin patches. Each of these was in turn mixed with the samples across the top and white was mixed into each mixture and pulled down to better see the resulting colour. In the case of Viridian, the mixture was made to a neutral grey. Similar proportions were made for each other colour set.
It seems that Quin Red makes a much more brilliant or cleaner colour. Both Permanent Alizarin and Alizarin leave a dirty, blackish undertone. In the mixtures this condition continued. The near complements of Viridian and all the "Alizarins" seemed to mix beautiful greys in each case. Good cool colours. When mixed with Ultramarine violets resulted. Quin Red produced the cleanest most brilliant violets. When mixed with Cad Yellow Deep the colours with Quin Red were far cleaner.
By themselves both Alizarin and Permanent Alizarin are a deeper value and rich cool reds. If that is important to your methods, Permanent Alizarin is perhaps for you. In mixtures the full range of values are available for all the "Alizarins". It will be interesting to see how transparent passages work - for example in skies.
Both Permanent Alizarin and Quin Red are more expensive pigments. They are Quin based (organics made in the lab).
The pigments tested were Stevensons Alizarin (no longer being made), Gamblin's Permanent Alizarin (a different richer formulation from others investigated), and Gamblin's Quin Red (Others seemed quite similar in value, hue, and the mixtures).
I will paint with both the substitutes for a while before making a decision. Let me know your experiences.