Oil paint can be profitably judged for either its covering strength or transparency. This comports with some well known bits of studio wisdom: “fat over lean,” and “thick lights, thin darks.” Covering colors, often called ‘body’ colors, hide everything beneath them. Transparent colors modify what is beneath them while leaving them visible. In watercolors, transparent qualities are extremely important. Examples of covering colors include whites and cadmiums. Examples of transparent colors include alizarin crimson, earth green, and indian yellow.
Contrasting thick and thin passages give charm to oil paintings. Figure paintings with loaded lights and thin or transparent darks can achieve startlingly lifelike results. All this is say that dark colors that are transparent are important to oil painters.
One of my favorite colors is Rembrandt Oils’ raw umber. Rembrandt’s version of this important color is very transparent, which makes it excellent for all warm-toned darks.
Another brilliantly transparent dark is Williamsburg’s Quinacridone Gold. Here’s one of my old tubes of the paint. These days Williamsburg calls this ‘Quinacridone Gold Brown.’ The current version contains the pigments PR206-Quinacridone Pyrrolidine Red, and PO48-Quinacridone Gold. I think my older version consists solely of the latter pigment. A great source for information about pigments is Handprint.
This orange-brown paint handles exceptionally well and is wonderfully transparent–a great paint.
I decided to buy another tube but was shocked to learn that this earth color is expensive–$50.00 for a 37ml tube! Earth colors, even from the most expensive brands are always modestly priced. A 40ml tube of raw umber from Old Holland is $14.00 for example.
Here’s Williamsburg’s prices taken from Dick Blick:
The Quinacridone compound first saw use in paint in the ’50’s. When car manufacturers stopped using Quinacridone Gold (PO49) in the early 00’s, pigment makers stopped producing the pigment. When paint makers exhaust their existing stocks, there won’t be any more of this wonderful pigment.
PO 48 is no longer being made. If you really like paints made with it, now is the time to stock up. One can’t compare the price of iron-based “earth” paints with quinacridones. Iron oxides are extremely cheap for an art materials company to purchase from industry. The transparent ones are more expensive but the opaque ones are incredibly cheap.
PR 206 isn’t being made anymore either. Since this Williamsburg paint has both extinct pigments, the price increase may be due to anticipated and/or real demand.
Golden is reformulating some of their paints to mimic these formulations made with extinct pigments using transparent iron oxide red, plus quinacridone magenta, plus phthalo green blue shade (to give one example the company posted). These mimic formulations seem pretty close but the tiny amount of phthalo green is a red flag, especially in watercolor. It will be interesting to see lightfastness testing to see how the fading of the green impacts these. Also, diluted quinacridone magenta isn’t going to have the world’s best lightfastness either, especially if one mixes these mimic paints with white.