Friday, August 13, 2010

I am curious, yellow

image from webexibits.org

The post on black was the first of several I want to do on the nature of the various pigments. Tonight I want to talk about yellows.

The yellow that you will most likely have on your palette is cadmium yellow, which is a metal, cadmium sulphide, it becomes deeper with the addition of selenium. Cadmium is a heavy metal and toxic. The usual advice follows, don't smoke or eat with cadmium on your hands and don't hold brushes in your mouth. Many of our paints are toxic so there is nothing unusual about this. A number of years ago Daniel Moynihan, senator from New York tried to get a bill passed that would have made cadmium pigments illegal. It didn't fly, thankfully.

Most of the use of cadmium is in cadmium-nickel batteries. It was commonly used to color plastics and has been a problem in children's' toys imported from our comrades the Chi-coms. There is no good substitute for this permanent and stable pigment. Before cadmium was available artists used chrome yellow. That has been completely replaced by cadmium.

Cadmium yellow comes in different hues. Even though they bear the same names, the actual hues vary from one brand to another. The usual variations are cadmium yellow pale, light, cadmium yellow lemon, cadmium yellow, medium and deep. They grow warmer and redder as they go from light to deep. I usually have only cadmium yellow on my palette. If I add another it is cadmium yellow medium.

Cadmium yellow is what I think of as a pure yellow, cadmium medium seems a little orange to me and cadmium light or pale is too light to get the punch I want. A lot of landscapists like cadmium yellow lemon, but I feel that if I want a cadmium yellow that is cool, I can add my own blue. Cadmium yellow is about in that sweet spot that is not too warm and not too cool. I modify it to go either direction with other colors from my palette.There are many painters out there who use limited palettes that have three colors, cadmium yellow is almost invariably one of them.

Cadmium yellow is a relatively expensive color but I don't churn through it like I do ultramarine. I buy about a quart a year from RGH (link in my sidebar). Quality is important in cadmiums. The student grades really fall down here, avoid them, you need to buy a professional grade. Most of the available brands that are professional quality make a decent cadmium yellow. Never buy cadmium yellow hue. When it says hue on the tube that means it is a mixture of who knows what that LOOKS like cadmium yellow but is not. It will not mix right and will lack pigmenting strength. It will however, be cheap.

Another yellow that I occasionally use is Naples. Naples yellow is now difficult to find. It is made from lead and the tube should feel very heavy. Every company still seems to market a Naples yellow but most are not real. They are about the right color but they don't act the same way when you use them. Naples is a soft and subtle color that is great in skies. It is not a very powerful pigment but is great for modifying other notes. The boutique manufacturers still make it though, so does RGH. It is essential to get the real thing though, the charm of Naples is in its peculiar subtlety and the synthetic versions don't have that. It generally comes graded light, medium and deep. The deep approaches raw sienna in color, the light is very pale and the medium is about right.

Azo yellow is a common and less expensive substitute for cadmium, other than its price, which is lower than cadmium it has nothing to recommend it. It seems to me inferior to cadmium in every way. It is less toxic though. Many companies market a yellow with their brand name on it that is generally an azo mixture of some sort.

26 comments:

Caroline Bray Art said...

Hi Stape! Here I am enjoying your posts as usual! I wondered if you could advise on the best way of getting cadmium off your hands? I currently use soap and hot water and scrub with a nail brush if it's being stubborn. Is there a better way? Are there any gloves suitable for painting in? I'm an avid cook but I don't like the idea of poisoning myself and my fiance. Thank you!

Philip Koch said...

Cadmium yellow rocks! And as Stape says, those substitutes are just awful. When you need s strong yellow, you need a STRONG yellow.

Caroline, I use those disposable rubber gloves when I paint. The kind they sell in drug stores in boxes of a hundred. They're cheap and keep your skin from falling off from excess scrubbing. As one gets older one's skin naturally dries out. The gloves help.

Lucy said...

I too use the gloves. Stapleton, which brand of Naples yellow do you prefer? Of all the colors, naples yellow seems to have the most wild differences in hue from maker to maker. The "true" naples does have a different quality, perhaps because of the luminosity of the lead. Another good reason to wear gloves.

Thank you!

Jean Spitzer said...

I like the cheap nitrile gloves sold in hardware stores.

Mike Thompson said...

Rats! I opened your blog and thought you were going to branch out into semiconductor theory today.

Of course, cadmium and Naples yellows are opaque which suits your style of direct painting extremely well. In these hundreds of posts I think you might have mentioned glazing once or at most twice, or maybe I imagined it, but I think it is safe to say that you probably don't glaze a lot. Then there is the luminosity you get by using transparent glazes over the basic white of the canvas. IIRC, glazes are transparent, scumbles are opaque. The more transparent yellows lack the punch of cadmiums but a cadmium glaze might kill the sought after effect these 'lesser' pigments provide.

What is confusing, though, about tinting strength is that it takes an opaque cadmium to give a strong yellow but the pthalo greens and blues and Prussian blue are all transparent and anything more than a whiff of these pigments turns your paint puddle brilliant green or blue faster than an electron recombining with a hole as they are swept through the base-emitter junction in a bipolar junction transistor.

And then there is the problem that most of the transparent pigments look very dark on their own until thinned down to transparency or mixed with an opaque. Yellow doesn't seem to do this, except NICKEL azo yellow which is tan to brown in bulk but brilliant yellow when extremely thin.

One more comment and then I'll activate the keyboard cattle prod. I believe it was the German government that made the German pigment manufacturer upgrade the emissions of their manganese blue operation for environmental safety. They made so little MB relative to the cost of the upgrade that MB has totally disappeared - only the dreaded hues are available because this pigment was sole sourced. Now the closest we come to this color is to hear old timers wistfully extol its magical properties. Since our elected officials seem hellbent for leather to protect us from ourselves, cadmium should be called an endangered pigment too.

John Hannafin said...

Stape, Do you ever paint using protective gloves? I don't but I wonder if frequent painting with certain pigments sometimes getting on your hands could be dangerous? Thanks!

Bob Carter said...

Cadmium’s toxicity arises when there are Cd2+ ions in solution, which are produced when soluble cadmium compounds dissolve in water. Fortunately, the sulfide and selenide of cadmium (CdS and CdSe) are among the least soluble ionic compounds. The Merk Index lists the solubility of CdS as 0.13 mg/100g water at 18 degrees Celcius, which is 1.3 ppm. That’s not much of a hazard. However, the solubility increases in acidic solutions, as in your stomach. So, ingesting it or inhaling the powder is hazardous. (Do not grind this pigment yourself!) I don’t worry about cadmium on my hands, because CdS and CdSe are not absorbed through the skin. It’s prudent to wash it off of your hands before eating, using dish washing liquid (e.g., Palmolive, Dawn) to cut the oil it’s in. Even if you didn’t get every speck, the little you might ingest would pose a minimal hazard. It’s just not a good idea to make it a habit. Yes, wash it off if you smoke (do people still do that?), but then again you’re probably getting more cadmium from the smoke than from your hands. And if you smoke, how seriously can we take your health concerns?

MCG said...

Any thoughts on Indian yellow? I rarely see it used these days and I only use it on occasion. I wonder if thats a result of prolific direct painting/painters? Curious if you've used it much and for what...

Judy P. said...

Enjoyable post as usual, and comments too!
Cad yellow hue is NOT cheap! It came with my starter kit, and mindlessly I just kept buying it when I ran out. It is such a poor mixer that I ran through 3 tubes before replacing any of the other colors; finally I got a real cadmium yellow, and was surprised that a little dab'll do ya.

Tim said...

Is the next post gonna be on blue? I am quite surprised that you knew so much about Swedish culture! Kudos!

jeff said...

Stapleton when you say Cadmium Yellow are talking about Yellow light?
I noticed on the RGH site that they have light, medium, and dark.

Winsor Newton sells a pure Cadmium Yellow that is darker than the light and not as Yellow/Red as medium.

They also sell a Primrose which looks interesting.

Todd Bonita said...

This is bizarre..I was researching yellows two days ago on the web to learn which is redder and which is greener. Thank you for this post Stape... "is there a yellow that is greener" ?

...also...

I heard through a good source that you invented a color called "Porn star pink"? Can you confirm or deny these allegations.

Stapleton Kearns said...

Caroline:
I use Goop, mechanics hand cleaner. Get it at the auto parts store or Walmart. It is a wonder product!
.................Stape

Stapleton Kearns said...

Philip:
Yes the yellow really has to be right doesn't it. No room for compromise on this one.
.................Stape

Stapleton Kearns said...

Lucy:
I haven't bought Naples in a while so I will have to get back to you. It has become hard to find.I would start with RGH. They happily sell lead paint in all its forms so I expect their Naples is good too.Except for my white, theirs is the only paint I buy.
.................Stape

Stapleton Kearns said...

Jean;
I buy the "Raven" brand at the auto parts store. They are durable and come in black which makes me look tougher.
..Stape

Stapleton Kearns said...

Mike;
I may do semiconductors soon, stay tuned. What exactly are they?
You are correct I paint mostly opaquely and I don't use Indian Yellow.I have on occasion and it is a nice glowing color though. I have a big palette now though and choices have to be made somewhere. I keep one corner of my palette for visiting colors that I am either experimenting with, or have for a special purpose.
....................Stape

Stapleton Kearns said...

John:
I often paint in Nitrile gloves. Not because of the poison aspect, just because I get sick of having paint on my hands all the time.
..........Stape

Stapleton Kearns said...

Bob:
When I posted that picture I KNEW it would bring you out of hiding. And here you are, good to hear from you!Thanks for the explanation of the toxicity of cadmium yellow. I actually knew about the solubility thing but didn't feel comfortable including it as I am not too hip to chemistry and peoples well being depended on my getting it right.
........Stape

Stapleton Kearns said...

MCG;
The colors I use are mostly those that I grew up with and have learned to use.
...........Stape

Stapleton Kearns said...

Judy;
That is true. I never use hues, because I value the pigmenting strength of the real thing.
................Stape

Stapleton Kearns said...

Tin;
I grew up in Sweden. Well almost, Minnesota.
...................Stape

Stapleton Kearns said...

Jeff:
I am currently using the medium, but for many years I used the light. It is a matter of personal choice though. Either one will work just fine. I do feel the deep is a bit to red for my purposes. If I want a warmer version I will go all the way and use a cadmium orange.
..............Stape

Stapleton Kearns said...

Todd;
Cadmium lemon is a cooler greener version.Yes I hav e to admit I carry a color I make myself that I cal pornstar pink. It is a hot pink color that I use as an anti-green. It is really loud looking and I only use it for stepping on other colors.It is also useful in snow and at the bottom of skies.. Several of my friends like it too, so I have to cook up big batches of it when I do make it. Williamsburg Persian Rose is about the same color and if you want to try it that is what to get.
.............Stape

Caroline Bray Art said...

Thanks for the tip, Stape! I can't wait to walk into Walmart and say, 'Can I have some Goop please?' It's such a good word. I'll invest in some gloves as well.

Nameless Art said...

I know this is an old thread but it's relevant for me today. I prefer a muted colors and usually stuck with yellow ochre. in a recent alla prima class the teacher says she only uses cadmium yellows ( a light and medium) and this seems to work well for opaque direct painting. I'd appreciate any suggestions for warm yellows to glaze with. I've been using Indian yellow by m graham, which is a beautiful vibrant orange color , mixed with raw umber and alizarin crimson for a really dynamic brown. As for Naples yellow winsor newton makes a good one, van goghs is terrible.