Re: Traditional palette vs. modern 583 by Ed on 05/26/01 at 10:03 PM
Re: Traditional palette vs. modern

In Reply to: Re: Traditional palette vs. modern posted by Steve Sauer on 05/26/01 at 3:07 AM:

"This statement is erroneous."
Look, I don’t want this to degenerate any further into what is increasingly obvious is a p***ing contest but my statement is absolutely correct - Vermillion CAN BE impermanent. This is irrefutable. Even the most basic research on the matter will show this to all but the most blinkered. Mercuric sulphide STARTS has a natural black form, if you have any doubts check here (pay particular attention to the second paragraph under Chemistry of Pigment):
http://www.sewanee.edu/chem/Chem&Art/Detail_Pages/Pigments/vermillion

And if you want incontrovertible truth of the darkening of the pure pigment in use in oil painting check this link out. I knew it would come in handy:
http://www.amolf.nl/research/biomacromolecular_mass_spectrometry/molart/Still-life.html

"There must be a cause. If some have not blackened, then Vermilion cannot be light sensitive in itself. I doubt these old paintings have been stored in utter darkness since they were painted."
Then Vermilion cannot be light sensitive in itself? Don’t be daft. A lot of chemistry is like this, without knowing the minutiae of the history of a painting from the origin of the pigment through its use and subsequent ageing to the present day it may be impossible to know what causes a given effect but it is enough to know IT DOES OCCUR. And as I’m sure know, if an oil painting was stored in the dark it would only cause the linseed oil to yellow and darken.

"...Put them in a contest with pure carbon, and I bet the carbon would win."
Let’s not be facetious shall we? I have seen a couple of examples of Phthalocyanine blues subjected to the most severe environmental test one could image - a decade at least of full-time daylight and environmental exposure at a tropical latitude with very little if any fading (there was no control to compare it to). Very few pigments could hope to withstand that kind of punishment and I’d bet my car Vermillion wouldn’t.

"Put them in a heat test against cobalt blue, and I would think cobalt would win."
This is a specious argument. Were you planning on heating your paintings any time in the future to the temperatures you might require for this? Besides, the linseed oil would fail a hell of a lot sooner than these pigments might. You might also like to research the temperature changes in Ultramarine and Cobalt Blue before you make this assertion in public. Phthalocyanine compounds are noted for their thermal stability.

"And, many people will not use Cobalt Yellow, because they don't consider it permanent enough."
I don’t personally - I am one of those ASTM I or nothing people you refer to. I stand by what I said though, ASTM II is better than merely reasonable permanence by most standards and is classed by them as 'very good lightfastness'. There are some possible interactions with other pigments which make it not reliable enough for my taste, even if I had need of its hue slot which I already have filled.

"The ASTM ratings are useful, but they are not omniscient."
No, I didn't say they were. They have even made a few gross errors apparently, thrown up by other tests. But as an industry-standard it’s a very good start and since it’s the only independent test we can refer to it’s the best we have at the moment. ASTM I is for no discernible change after 100 years of museum-quality lighting.

"My point is clear."
I didn’t miss your point, but your statement is misleading, that is MY point. It’s the inherent weakness of the lead pigment that is at fault here (weakness = reactivity).

"Free sulphur and polluting sulfur compounds may contribute to Vermilion's poor reputation for mixing with white lead."
Yes but you’re missing the whole point - even in the absence of sulphur it can still turn black as you will see if you check out the links above.

"I saw that test site; Vermilion was not tested, was it?"
I didn’t say it was, I said I was redoing the tests myself to check the reliability of my own palette, including Ultramarine and Flake White which is supposed to be a no-no.

"I have already provided many explanations and you've denied them all."
Yes, because you’re making leaps which cannot be backed up by logical argument and analysis.

"The fact that many examples of lightfast Vermilion exist proves that the compound mercuric sulfide is lightfast."
What a specious statement this is! You need to brush up on your rhetoric - something does not have to go wrong EVERY TIME for it to be proven to go wrong.

"If it was not lightfast, every example of Vermilion would have blackened."
Where did I say mercuric sulphide spontaneously turns black over time? Hmmmm? Nowhere. I said given certain conditions it CAN, which is not reliable enough for me. Since light appears to be the single most important factor it’s a fairly transparent issue in my book.

You missed my point about the colourmen, they went looking for a replacement to vermillion at least a century before there was an ASTM, primarily because of its poor reputation (this has been widely known since at least the 15th century). Nice to see you finally acknowledge the toxicity of Vermillion by the way.

"When there are examples of bright red Vermilion on paintings that are hundreds of years old and I have Naphol paints that fade in a few months or even weeks, I am less inclined to blindly trust ASTM ratings."
Good for you, it’s a good idea not to blindly trust the ASTM ratings. PR9 does not have a particularly good reputation but there are many other modern reds that do.

"Quinacridone "Permanent Alizarin Crimson" looks and performs nothing like real Alizarin."
If you are referring to Quinacridone Red or Violet (PV19) I would agree. Quinacridone Carmine (PR N/A) on the other hand, along with Anthraquinoid Red (PR177) are both apparently very similar in transparency and a close or very close match in masstone AND undercolour. I personally use the PR177, W&N's choice for Permanent Alizarin Crimson in oils and since I was lucky enough never to use to the real pigment it works fine for me. It also has a sterling reputation which I hope is borne out by further testing.

"Insoluble mercury is a whole different matter."
Mercuric sulphide is not insoluble, it is classed as inorganic. It is still a highly toxic, dangerous substance and FAR more toxic than cadmium and lead compounds, both of which are dangerous only by inhalation or ingestion. Inorganic mercury compounds are toxic by skin contact as you would know if you bothered to fully read that link I provided in my last post. Unless you were planning on wearing a HazMat suit, in a cleanroom with positive air pressure, while you ground your colours...

"Should I sue my dentist for putting mercury-containing fillings in my teeth?"
You're being specious again. There is a world of difference between a solid silver-mercury amalgam and grinding your own pigment as YOU suggested. And there is mounting evidence that mercury outgassing from fillings, particularly in people who grind their teeth in their sleep, is a contributing factor in a host of ailments.

"Why not list the effects of cadmium in the body?"
Because they are not relevant. In case you missed it I said 'While I wouldn’t suggest cadmium is not a health risk'. The fact remains it is far less of a risk than mercury.

"Those are quotes from your source.. "
You conveniently missed the most important point: 'Inorganic mercury can be absorbed through the gastro-intestinal tract but ALSO THROUGH THE SKIN.' That's fairly significant in this context don't you think?

You attempted to skirt the issue of the toxicity of mercuric sulphide by muddying the waters with other pigments and what you said is patently false -"Grinding cadmium colors is just as toxic", not when you don’t have to protect your skin from contact with the pigment it isn't.

"Organic mercury is not relevant to this discussion! Flake white is more dangerous than Vermilion because it is organic and contains soluble lead."
Since lead white is ONLY toxic through inhalation and ingestion but mercuric sulphide is toxic by skin contact, it poses a significantly higher risk. You think inorganic mercury remains unchanged inside the body?

"That's 5 pigments. 5 Pigments just for Phalo."
Nice attempt at sidestepping. But that's hardly 30.

"As you said, reputable dealers are selling fugitive paints. Easy? Hardly.."
I said it is easily within one's grasp - one book or a single day spent with a couple of decent search engines to determine a reliable basic palette hardly requires a degree in rocket science.


Follow Ups:

Re: Traditional palette vs. modern Steve Sauer   Posted at: 05/27/01 (1)
Re: Traditional palette vs. modern Ed   Posted at: 05/28/01 (0)

Post a Followup 545,548,555,560,565,566,573,582,583"> Ed"> ed1177_yahoo.co.ukRe: Traditional palette vs. modern_05/26/01 at 10:03 PM"> "Re: Traditional palette vs. modern"
: "This statement is erroneous." : Look, I don’t want this to degenerate any further into what is increasingly obvious is a p***ing contest but my statement is absolutely correct - Vermillion CAN BE impermanent. This is irrefutable. Even the most basic research on the matter will show this to all but the most blinkered. Mercuric sulphide STARTS has a natural black form, if you have any doubts check here (pay particular attention to the second paragraph under Chemistry of Pigment)http://www.sewanee.edu/chem/Chem&Art/Detail_Pages/Pigments/vermillion : And if you want incontrovertible truth of the darkening of the pure pigment in use in oil painting check this link out. I knew it would come in handyhttp://www.amolf.nl/research/biomacromolecular_mass_spectrometry/molart/Still-life.html : "There must be a cause. If some have not blackened, then Vermilion cannot be light sensitive in itself. I doubt these old paintings have been stored in utter darkness since they were painted." : Then Vermilion cannot be light sensitive in itself? Don’t be daft. A lot of chemistry is like this, without knowing the minutiae of the history of a painting from the origin of the pigment through its use and subsequent ageing to the present day it may be impossible to know what causes a given effect but it is enough to know IT DOES OCCUR. And as I’m sure know, if an oil painting was stored in the dark it would only cause the linseed oil to yellow and darken. : "...Put them in a contest with pure carbon, and I bet the carbon would win." : Let’s not be facetious shall we? I have seen a couple of examples of Phthalocyanine blues subjected to the most severe environmental test one could image - a decade at least of full-time daylight and environmental exposure at a tropical latitude with very little if any fading (there was no control to compare it to). Very few pigments could hope to withstand that kind of punishment and I’d bet my car Vermillion wouldn’t. : "Put them in a heat test against cobalt blue, and I would think cobalt would win." : This is a specious argument. Were you planning on heating your paintings any time in the future to the temperatures you might require for this? Besides, the linseed oil would fail a hell of a lot sooner than these pigments might. You might also like to research the temperature changes in Ultramarine and Cobalt Blue before you make this assertion in public. Phthalocyanine compounds are noted for their thermal stability. : "And, many people will not use Cobalt Yellow, because they don't consider it permanent enough." : I don’t personally - I am one of those ASTM I or nothing people you refer to. I stand by what I said though, ASTM II is better than merely reasonable permanence by most standards and is classed by them as 'very good lightfastness'. There are some possible interactions with other pigments which make it not reliable enough for my taste, even if I had need of its hue slot which I already have filled. : "The ASTM ratings are useful, but they are not omniscient." : No, I didn't say they were. They have even made a few gross errors apparently, thrown up by other tests. But as an industry-standard it’s a very good start and since it’s the only independent test we can refer to it’s the best we have at the moment. ASTM I is for no discernible change after 100 years of museum-quality lighting. : "My point is clear." : I didn’t miss your point, but your statement is misleading, that is MY point. It’s the inherent weakness of the lead pigment that is at fault here (weakness = reactivity). : "Free sulphur and polluting sulfur compounds may contribute to Vermilion's poor reputation for mixing with white lead." : Yes but you’re missing the whole point - even in the absence of sulphur it can still turn black as you will see if you check out the links above. : "I saw that test site; Vermilion was not tested, was it?" : I didn’t say it was, I said I was redoing the tests myself to check the reliability of my own palette, including Ultramarine and Flake White which is supposed to be a no-no. : "I have already provided many explanations and you've denied them all." : Yes, because you’re making leaps which cannot be backed up by logical argument and analysis. : "The fact that many examples of lightfast Vermilion exist proves that the compound mercuric sulfide is lightfast." : What a specious statement this is! You need to brush up on your rhetoric - something does not have to go wrong EVERY TIME for it to be proven to go wrong. : "If it was not lightfast, every example of Vermilion would have blackened." : Where did I say mercuric sulphide spontaneously turns black over time? Hmmmm? Nowhere. I said given certain conditions it CAN, which is not reliable enough for me. Since light appears to be the single most important factor it’s a fairly transparent issue in my book. : You missed my point about the colourmen, they went looking for a replacement to vermillion at least a century before there was an ASTM, primarily because of its poor reputation (this has been widely known since at least the 15th century). Nice to see you finally acknowledge the toxicity of Vermillion by the way. : "When there are examples of bright red Vermilion on paintings that are hundreds of years old and I have Naphol paints that fade in a few months or even weeks, I am less inclined to blindly trust ASTM ratings." : Good for you, it’s a good idea not to blindly trust the ASTM ratings. PR9 does not have a particularly good reputation but there are many other modern reds that do. : "Quinacridone "Permanent Alizarin Crimson" looks and performs nothing like real Alizarin." : If you are referring to Quinacridone Red or Violet (PV19) I would agree. Quinacridone Carmine (PR N/A) on the other hand, along with Anthraquinoid Red (PR177) are both apparently very similar in transparency and a close or very close match in masstone AND undercolour. I personally use the PR177, W&N's choice for Permanent Alizarin Crimson in oils and since I was lucky enough never to use to the real pigment it works fine for me. It also has a sterling reputation which I hope is borne out by further testing. : "Insoluble mercury is a whole different matter." : Mercuric sulphide is not insoluble, it is classed as inorganic. It is still a highly toxic, dangerous substance and FAR more toxic than cadmium and lead compounds, both of which are dangerous only by inhalation or ingestion. Inorganic mercury compounds are toxic by skin contact as you would know if you bothered to fully read that link I provided in my last post. Unless you were planning on wearing a HazMat suit, in a cleanroom with positive air pressure, while you ground your colours... : "Should I sue my dentist for putting mercury-containing fillings in my teeth?" : You're being specious again. There is a world of difference between a solid silver-mercury amalgam and grinding your own pigment as YOU suggested. And there is mounting evidence that mercury outgassing from fillings, particularly in people who grind their teeth in their sleep, is a contributing factor in a host of ailments. : "Why not list the effects of cadmium in the body?" : Because they are not relevant. In case you missed it I said 'While I wouldn’t suggest cadmium is not a health risk'. The fact remains it is far less of a risk than mercury. : "Those are quotes from your source.. " : You conveniently missed the most important point: 'Inorganic mercury can be absorbed through the gastro-intestinal tract but ALSO THROUGH THE SKIN.' That's fairly significant in this context don't you think? : You attempted to skirt the issue of the toxicity of mercuric sulphide by muddying the waters with other pigments and what you said is patently false -"Grinding cadmium colors is just as toxic", not when you don’t have to protect your skin from contact with the pigment it isn't. : "Organic mercury is not relevant to this discussion! Flake white is more dangerous than Vermilion because it is organic and contains soluble lead." : Since lead white is ONLY toxic through inhalation and ingestion but mercuric sulphide is toxic by skin contact, it poses a significantly higher risk. You think inorganic mercury remains unchanged inside the body? : "That's 5 pigments. 5 Pigments just for Phalo." : Nice attempt at sidestepping. But that's hardly 30. : "As you said, reputable dealers are selling fugitive paints. Easy? Hardly.." : I said it is easily within one's grasp - one book or a single day spent with a couple of decent search engines to determine a reliable basic palette hardly requires a degree in rocket science.

 
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