Chalkiness of Colors Lightened with White

I'm sure we all have a story about the frustration of lightening colors with white, and the resulting colors appearing very chalky. Mine was always the frustration of painting red roses with chalky pink highlights.

I did some experimenting with ways to reduce the problem and have some swatches of colors to show you using cadmium red and hookers green. I did these with acrylics to expedite drying time, but the same principles apply to water-soluble oils. In either case, the under painting must be completely dry before putting on the next layer.

One note, the photos of the swatches don't show the effects as well as in real life, but you can experiment yourself once you have the idea.

Cadmium Red Medium

The cad red over the titanium white maintained its slight orange cast, while it seemed to pick up a slight bluish cast when mixed with the titanium white and had a chalky appearance. When mixed with zinc white that is less opaque than the titanium, it still became slightly bluish and chalky but not as much.



While the Hookers green maintained a greenish-yellow hue over the titanium white, when they were mixed, the green became more like a mint green with a bluish cast and chalkiness.

One way to liven up the colors you may all ready have down if they are chalky is to do a thing glaze of pure pigment over the chalky color. It can be the same pigment or another if you want to change the color to a different hue.

Here is a test I did glazing the cad red medium over the mixed reds. It is hard to see and I probably didn't make the glaze thin enough, but you can get the idea from it.

Some thoughts:

One of the things you're losing when you mix some pigments like cad red with titanium white is color saturation, hence the "chalkiness." The white by itself is not purely neutral in tone either.

Zinc is often used as an alternative but has its own problems, such as less opacity and known problems with stability (don't use too much.) Lead white is another pigment for oils but not offered in any miscible paints. Holbein has a strontium white ("ceramic") pigment that is about as transparent as zinc but more like titanium in tone; however, it's more expensive than either of those. Another thing is that some brands mix their whites or may use fillers like barium. The oil vehicle is also often safflower which limits its application (not intended for underpainted layers) and slows the drying time. Several issues to consider.

You mention some good alternatives such as thinning the paint or using glazes. What this gives you is the advantage of using the brighter tone beneath to your advantage. That can be the white of the ground or any lighter value color. You can take further advantage of this effect by using a different pigment that is more transparent.

Other pigments also mix differently with titanium than cadmiums, like naphthol, quinacridone, or in the case of green, phthalo. These pigments are not as prone to lose their saturation level quite as easily.

Judy, thank you so much for this demo, and the video from Mike Rooney. I have seen the video he did on color mixing before. All, of these are very helpful.

David, I really appreciate the information on the whites, especially Holbein's Ceramic White. I think I'll buy a tube and check it out.

Eveyone is so thoughtful and kind with their information. I really appreciate it.

Dayle

I have been experimenting with porting a technique used in oil painting to help with the chalkiness problem: creating a paste with oil and calcium carbonate (chalk, marble dust, etc.) and combining this with tube paints to lighten/open up the color without so much chalkiness. A starting point is a 1:1 mix of tube paint and putty, but Titanium white can be cut substantially more. I find it effective, but it takes some experimentation and affects paint handling. The effect is almost like an aeration of the color, and while I still need white, I can use much less.

I am using Holbein Duo paints for plein air work and so far have used their modified linseed oil to make the paste, assuming it should be compatible. The calcium carbonate came from Graphic Chemicals but is available from a number of places including pigment suppliers. For oil painting, I have read that the oil is best if heat-bodied or sun thickened; I have not so far used this type of oil with putty for WMOs except for adding a small amount of heat-bodied walnut oil. I'm not certain if too much of a non-modified oil will affect the water cleanup of WMOs; something I need to experiment with.

The basic info about this putty came from Tad Spurgeon's website. Natural Pigments makes commercial versions of the paste (Velasquez and Impasto mediums), but it is quite easy to make. They also make a product called Oleogel I would like to try with WMOS for similar reasons.

I am in unknown territory as far as whether this is sound practice with WMOs. As far as I understand, with oil paints, the paste both buffers and strengthens the paint film so is sound practice with extensive historical precedent, but WMOS may not perform the same. Has anyone else out there experimented with this approach?

No, I haven't, but thank you for the information!

This is a wonderful discussion everyone... like it...

Thanks Judy for starting this...

Thank you Jay for such a comprehensive discussion of what you have been experimenting with. I've never tried it and can't say how it may react in WSO.

I do use only walnut oil because I don't tolerate even modified linseed oil because of allergies. I have no problem with soap and water cleanup with the walnut oil, but I just naturally use only small amounts if needed in the upper, fatter layers of paint.

Keep us posted on your progress.

Thanks Faisal, also. I hope the discussion has been of help to a lot of the viwers.

Judy