Re: Traditional palette vs. modern 566 by Steve Sauer on 05/22/01 at 5:36 PM
Re: Traditional palette vs. modern

In Reply to: Re: Traditional palette vs. modern posted by Ed on 05/22/01 at 5:11 PM:

"Your point about purity of pigment is well taken but even without any pollutants it can be make the irreversible change to the black form when exposed to light."

What causes that color change? There must be a reason. Mercuric iodide scarlet is light sensitive, but there are plenty of examples of Vermilion in paintings that are hundreds of years old that are quite red and not black at all. That means mercuric sulfide is not light sensitive. If it was, all samples of Vermilion would have blackened.

"Sure it can be reliable when used correctly - adequate protection from the medium/varnish"

Emerald green, Orpiment, Realgar, Verdigris, Malachite, Azurite, etc.. Not Vermilion. It doesn't out-gas like orpiment and realgar, and it's not an unstable compound like the copper greens. Varnish should not make a bit of difference with Vermilion.

"AND mixed knowledgeably"

Like any pigment. Only certain pigments like Titanium white are truly perfectly stable and can be mixed with anything. If perfect permanence was the only characteristic of a pigment that is valuable, we would all be painting with Titanium white instead of Flake, and using Cobalt or Cerulean Blue rather than any organic blue. etc. Reasonable permanence is acceptable. Cobalt yellow, for example...

"(its use with Flake White for example is potentially disastrous)"

The same thing is often said about cadmium colors, too. This is because Cadmiums and Vermilion are very similar chemically. They are both metallic sulfides. The free sulfur or polluting sulfides may react with lead white. Many people strongly warn against mixing cadmiums with lead white. Should we also not use cadmium colors?

Vermilion was traditionally mixed with lead white for flesh tones. How many painters did this successfully for hundreds of years before Naphol was even thought of? The only "disastrous" results occurred when the Vermilion was adulterated with read lead.

"but you are assuming a lot with the second point when talking about the majority of artists today! I’m not the only one who thinks its day as an artist’s pigment is long past."

True, but there are plenty who say the same thing about Flake White, and the cadmiums. Also, there are others who are very suspicious of many organic pigments because they have not been thoroughly tested or because they have certain undesirable properties (such as the tendency to fade in tints or mixtures).

"But apart from all of this, it is EXTREMELY toxic - your recommendation to grind your own paint would pose a severe health risk even with a level 2 respirator! You should look up the WHO guidelines for safe levels of mercury..."

Grinding cadmium colors is just as toxic. Of course, people need to know what they're doing. Mercuric sulfide is insoluble in water. This makes it far less dangerous than soluble mercury compounds. Flake white is actually far more dangerous to work with than Vermilion and painters just love to make their own flake white, don't they?

"Next you’ll be recommending we all go looking for genuine Emerald Green (amazingly also still available) just because Cézanne used it :-)"

Emerald green is far more toxic than Vermilion.

It contains both soluble copper and soluble arsenic. Vermilion contains insoluble Mercury. That's a huge difference.

Emerald green is certainly not suited for mainstream use today. However, it can be sufficiently lightfast and reliable if made properly and used correctly. But, it is far more incompatible with other colors and more unstable than Vermilion. Van Gogh used it, too. ;)

"Do you know the colour index number(s) of the paint you mention? Naphthol colours are not like the cadmiums - there is a range of ratings from pigment to pigment. Naphthol Carbamide, the one I specifically mentioned is ASTM 1. It’s also possible it may have been a mix along the lines of what you mention historically for Vermillion. As an example Naphthol AS-D (PR112) fared poorly under ASTM testing while Naphthol AS (PR178) rated ASTM I. That’s why a sound knowledge of the index numbers and their associated ASTM ratings is so important."

You argue against my points by arguing for the perspective of the amateur artist with a laissez-faire understanding of pigment chemistry and yet you expect people to know the fine details of 30 different types of Phalo or 20 types of Naphol? I'm exaggerating a bit, but there is a lot more complexity with regard to certain families of organics, because they come in many varieties.

Organic pigments like Naphol perform differently from the inorganic pigments they "replace." Some are excellent replacements; some are not.


Follow Ups:

Re: Traditional palette vs. modern Ed   Posted at: 05/23/01 (4)
Re: Traditional palette vs. modern Steve Sauer   Posted at: 05/26/01 (3)
Re: Traditional palette vs. modern Ed   Posted at: 05/26/01 (2)
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)
Re: Traditional palette vs. modern Steve Sauer   Posted at: 05/22/01 (2)
Re: Traditional palette vs. modern Ed   Posted at: 05/23/01 (1)
Re: Traditional palette vs. modern Steve Sauer   Posted at: 05/26/01 (0)

Post a Followup 545,548,555,560,565,566"> Steve Sauer"> sds_sds.comRe: Traditional palette vs. modern_05/22/01 at 5:36 PM"> "Re: Traditional palette vs. modern"
: "Your point about purity of pigment is well taken but even without any pollutants it can be make the irreversible change to the black form when exposed to light." : What causes that color change? There must be a reason. Mercuric iodide scarlet is light sensitive, but there are plenty of examples of Vermilion in paintings that are hundreds of years old that are quite red and not black at all. That means mercuric sulfide is not light sensitive. If it was, all samples of Vermilion would have blackened. : "Sure it can be reliable when used correctly - adequate protection from the medium/varnish" : Emerald green, Orpiment, Realgar, Verdigris, Malachite, Azurite, etc.. Not Vermilion. It doesn't out-gas like orpiment and realgar, and it's not an unstable compound like the copper greens. Varnish should not make a bit of difference with Vermilion. : "AND mixed knowledgeably" : Like any pigment. Only certain pigments like Titanium white are truly perfectly stable and can be mixed with anything. If perfect permanence was the only characteristic of a pigment that is valuable, we would all be painting with Titanium white instead of Flake, and using Cobalt or Cerulean Blue rather than any organic blue. etc. Reasonable permanence is acceptable. Cobalt yellow, for example... : "(its use with Flake White for example is potentially disastrous)" : The same thing is often said about cadmium colors, too. This is because Cadmiums and Vermilion are very similar chemically. They are both metallic sulfides. The free sulfur or polluting sulfides may react with lead white. Many people strongly warn against mixing cadmiums with lead white. Should we also not use cadmium colors? : Vermilion was traditionally mixed with lead white for flesh tones. How many painters did this successfully for hundreds of years before Naphol was even thought of? The only "disastrous" results occurred when the Vermilion was adulterated with read lead. : "but you are assuming a lot with the second point when talking about the majority of artists today! I’m not the only one who thinks its day as an artist’s pigment is long past." : True, but there are plenty who say the same thing about Flake White, and the cadmiums. Also, there are others who are very suspicious of many organic pigments because they have not been thoroughly tested or because they have certain undesirable properties (such as the tendency to fade in tints or mixtures). : "But apart from all of this, it is EXTREMELY toxic - your recommendation to grind your own paint would pose a severe health risk even with a level 2 respirator! You should look up the WHO guidelines for safe levels of mercury..." : Grinding cadmium colors is just as toxic. Of course, people need to know what they're doing. Mercuric sulfide is insoluble in water. This makes it far less dangerous than soluble mercury compounds. Flake white is actually far more dangerous to work with than Vermilion and painters just love to make their own flake white, don't they? : "Next you’ll be recommending we all go looking for genuine Emerald Green (amazingly also still available) just because Cézanne used it :-)" : Emerald green is far more toxic than Vermilion. : It contains both soluble copper and soluble arsenic. Vermilion contains insoluble Mercury. That's a huge difference. : Emerald green is certainly not suited for mainstream use today. However, it can be sufficiently lightfast and reliable if made properly and used correctly. But, it is far more incompatible with other colors and more unstable than Vermilion. Van Gogh used it, too. ;) : "Do you know the colour index number(s) of the paint you mention? Naphthol colours are not like the cadmiums - there is a range of ratings from pigment to pigment. Naphthol Carbamide, the one I specifically mentioned is ASTM 1. It’s also possible it may have been a mix along the lines of what you mention historically for Vermillion. As an example Naphthol AS-D (PR112) fared poorly under ASTM testing while Naphthol AS (PR178) rated ASTM I. That’s why a sound knowledge of the index numbers and their associated ASTM ratings is so important." : You argue against my points by arguing for the perspective of the amateur artist with a laissez-faire understanding of pigment chemistry and yet you expect people to know the fine details of 30 different types of Phalo or 20 types of Naphol? I'm exaggerating a bit, but there is a lot more complexity with regard to certain families of organics, because they come in many varieties. : Organic pigments like Naphol perform differently from the inorganic pigments they "replace." Some are excellent replacements; some are not.

 
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