Friday, September 3, 2010

More about hues and then chroma

Hugh Lofting 1886-1947

Last night we saw this Munsell three dimensional diagram of the colors.

However, and this is important. We don't paint with hues or pure colors, we paint with pigments. While it is possible to buy pigments that match the pure colors, generally painters work with paints that are the color of their ingredients. Many of the pigments the old masters used were nowhere near the pure hues on a color wheel. These pigments and others are nicely explained in a Gee-whiz video from Robert Gamblin.

I was asked in the comments how I think about mixing color. I use the hue, chroma and value system on my palette. I don't really think in three D but as I look at the note I am mixing I ask myself questions about the note I am mixing, like is it to high in chroma? or is it to grave? Is it to dark or is it higher in value? Is it yellow enough? I keep my as mixtures simple as I can. Hopefully a note can be made with two colors plus white, but often I need a smidgen of a third. I will do a post where I mix notes on my palette and show you that. But first I must dispense with the rest of the Munsell system.

The next criterion in chroma. Chroma is sometimes called saturation today, but I like the old words for things. Perhaps because those are the words I was taught as I formed my ability to mix colors, but mostly because they are elegant. Chroma is the ancient Greek word for color. Saturated is something that happens to bed sheets, and the press-board floors of cheap garden sheds.

The hues, located in that band, like the ring around Saturn, are lower in chroma as they move nearer the core of the color space. On that wedge of color cantilevered from the ring, the note marked 2 is graver (less colored, another elegant old word) than that note marked 10. As the notes move out from the core toward the outside they grow ever more colored. Yellow ocher is not very high in chroma, cadmium yellow is.

In many pigments it is generally not possible to raise the chroma. Take cadmium for instance, what would you do, add more cadmium? But you can reduce it's chroma, by adding gray or yellow ocher. So your pure cadmium yellow is as yellow as you can get with your palette. That means that pure cadmium yellow is on the outside edge of the color space creatable using your palette. The range of color that can be created with your selection of pigments is called the gamut. If you use only three dull earth colors, your gamut will be small. If you use the brightest modern pigments like pthalocyanine, you gamut will be large.

I will be holding a three day workshop at the Bass Harbor Campground in Bass Harbor, Maine. the 25-26-27th of September. That's Saturday-Monday. We will paint outside and I will teach beginners to experts the art of outdoor landscape painting.
Here is a link to where you can sign up.


Anonymous said...

hue are doing a great job! said...

I did figure out that I can raise the chroma of some cadmiums by adding a transparent paint pigments such as the Indian hues,pthalos,the new transparent reds etc. I finally found a good use for those transparent pigments. This is helpful to me because, in my still lifes , I am often looking at some very intense man made colors which I want to reproduce.

T Arthur Smith said...

This note's off topic, not to detract from the wonderful writing you're doing about paints and color. But I just found an old blog post about Winslow Homer you should see, if you haven't already. There are some good points. Just scroll down to the bottom of the page:

Stapleton Kearns said...

Thank hue.

Stapleton Kearns said...

Do you have something that will make a cadmium yellow yellower? Can salt be made saltier?

Stapleton Kearns said...

Y. Arthur;
I will check that out.