Alizarin Crimson 6 months later

[Einion]

Originally Posted by nit-wit

The question that springs to mind is: would a collector refrain from buying a painting where there is a use of AC?

How would they know? I don't think many artists make a point of mentioning specific colours are used (and it would seem counter-productive in this case!)

Einion

[Brian Firth]

Originally Posted by Daniel_OB

Thanks gunzorro
Yes, PR177 is very simillar to PR83. But the problem with PR177 is the same as with PR83, even as you said less, but the problem is still around, and it is: PR177 is not good when tinted (will fade too). Both should be used as mass tone only, otherwise bad supprise.
To make very white underlayer for alizarin to get higher value after glazing with tube PR177, will not work too. Paints with white underlayer fade faster...

Again, in my tests Winsor and Newton PR177 proved to be be absolutely lightfast, even in tints, while alizarin crimson faded in both tints and undertone in the same time (1 year of South facing sunlight). Winsor and Newton PR177 is lightfast and is lightfast in tints.

[nit-wit]

Originally Posted by Einion

How would they know? I don't think many artists make a point of mentioning specific colours are used (and it would seem counter-productive in this case!)

Einion

True, but I'd know if AC had been used, you would certainly know if AC had been used, and everyone else who's contributed to this post would know. But AC is such a useful colour it's a shame not to use it.

There's quite a lot of paintings that have 'altered' over time but it doesn't appear to affect their quality?? This VG church for instance has definately altered. I believe the path at least has faded considerably (according to a TV programme that I once watched). But the picture hangs together still quite well.



Andrew

[Einion]

Originally Posted by nit-wit

True, but I'd know if AC had been used, you would certainly know if AC had been used, and everyone else who's contributed to this post would know.

I'm one of the everyone else, I wouldn't know

I think you're assuming the Ali Crimson would be visible as itself, which would really only be if it were used alone or maybe mixed only with white.

In most mixtures, if the paint is blended uniformly, it's impossible to know what pigments were used merely by looking with the naked eye (excluding watercolour, where pigments can give other cues than their colour alone). If one knows the age of a painting, or has prior knowledge of the palette a painter favoured, a good guess can be made but you would not be sure. One cannot even tell the difference between many single-pigment colours and a mixed equivalent, if the latter is done properly.

Originally Posted by nit-wit

But AC is such a useful colour it's a shame not to use it.

Personally I think it's much more of a shame to have paintings fade within one's lifetime, especially when it can SO easily be avoided.

Originally Posted by nit-wit

I believe the path at least has faded considerably (according to a TV programme that I once watched).

Yes, it used to be pink wasn't it?

Einion

[nit-wit]

Originally Posted by Einion

I'm one of the everyone else, I wouldn't know

I think you're assuming the Ali Crimson would be visible as itself, which would really only be if it were used alone or maybe mixed only with white.

ok, point taken...

Originally Posted by Einion

Yes, it used to be pink wasn't it?

Einion

I think you're right - maybe based on Alizarin Crimson itself? I'm not up on Van Gogh chronology but AC was introduced in 1868 (Michael Harding says so) and maybe used by VG?

Andrew

[Daniel_OB]

Patrick1
I should note that lower down, the paint is intentionally applied extremely thin to get quick results; I thinned with artists' thinner.

What is artist's thinner?

[Patrick1]

Daniel, it's Demco odorless solvent for oil painting.

[Brian Firth]

Originally Posted by nit-wit

I think you're right - maybe based on Alizarin Crimson itself? I'm not up on Van Gogh chronology but AC was introduced in 1868 (Michael Harding says so) and maybe used by VG?

Andrew

In his letters to Theo, Van Gogh ordered three crimson pigments: carmine, crimson lake (alizarin crimson), and geranium lake. Unfortunately, of these three pigments alizarin crimson was the most lightfast, and considerably more lightfast at that. If he had used alizarin crimson, the path would probably still be pink, although lighter than his original vision. This painting, The Church at Auvers, was painted in June 1890. In his letter to Theo dated to April 29, 1890 Van Gogh ordered only two crimson pigments, Crimson Lake and the Geranium Lake. Which indicates by this time he had stopped using the fugitive carmine. Sadly, Van Gogh was most fond of Geranium Lake, which is an incredibly fugitive eosin dye lake, and this is most likely the pigment used in the path that has completely faded away.

[Smokin]

Are you trying to pretend that no paintings are retouched? Remember, I didn't say any example of an intense red in an old painting would be due to retouching, but some are.
As far as Hals and Rembrandt specifically - if you could point to individual works where it's known that madder lakes are present and that they're original please do, I'd like to see them.

My original comment was that alizerine crimson is seen in paintings that are centuries old, yours was "achem don't forget retouching". No, I wasn't implying retouching doesn't happen by laughing at that comment.

Source: Materials for Permanent Painting by DR. Maximillion Toch, uncle of Ralph Mayer, a scientist specializing in the chemistry of paints. Ch.21 The Failure of Sir Joshua Reynold's Paintings included his observations of Rembrandt's and Hals works.

Even if this were the case what they believed historically isn't relevant here.

Historical data is relevant, The synthetic is the same as the original in chemical structure and composition though it does have a slight difference in light fastness.

Yes, that has been posted before. I still await an explanation. There is no way that "Thinned: 7" is right for that if PG7 and PB15:1 are accurate.
This is the very type of thing that should make one question the anomalous results, not cause us to suddenly question all the other tests. PR83 is ASTM III

Funny, Ive posted links that clearly showed ASTM ratings that varied from 1-4 from various manufacturers for PR83 (Not just the one from OH ). Clearly, you are dismissing any information that contradicts the one you decided as true. I personally could care less what the light fastness rating says on kremers site, I know this pigment will fade in direct sunlight, but again, I also know it's a pigment that has stood the test of time quite well so long as the painting didn't crave a tan.

I made in post #20, fading in tints does have everything to do with functional light fastness.

You said alot there I couldn't understand. I said that if you add a pigment that is known to cause a pigment to fade and become fugitive, then that has nothing to do with light fastness. I don't know what you find confusing about that.

As far as the causes of fading are concerned, for the bulk of pigments used in artists' materials today, in typical usage, light is the major player

As far as you know..... yes we established this. But by your theory, any pigment with a light fast rating of 1, should have a permanence rating of 1 as well. So why does reality tell us different?

Alizerine, Prussian blue, Ultramarine, lead white, zinc, cobalt, ochre, are a few pigments that can all fade, change color, or dissolve into oblivion in total darkness. Every good source for information on pigments understands there is no "perfect pigment", just a better understanding of how to work with it. It took a long time to figure out what and why lead white was a good solid pigment to use and how it shouldn't be used. Same with virtually every pigment we have today that we now take for granted. Based on the history, I don't assume that any new pigment on the market will stand the test of time. So far, no pigment has ever just shown up and shined without any problems.

[Einion]

Originally Posted by Smokin

My original comment was that alizerine crimson is seen in paintings that are centuries old, yours was "achem don't forget retouching". No, I wasn't implying retouching doesn't happen by laughing at that comment.

Yes, because it might be down to later retouching; since you're acknowledging here this does occur I'm not sure why it elicited laughter when I first mentioned it.

In your first and second posts you made reference to the use of madder lakes by Hals and Rembrandt - the implication being that there were examples of "a very beautiful crimson color" that you'd referred to earlier - and if there are survivals of it, at this intensity, in very old paintings how this colour is still visible is a very pertinent point to this discussion. Because this is the inevitable outcome of a madder lake exposed to light given enough time (edges protected by frame):



Hence why I asked for examples where we know them to be original. I realise this is not something that we laymen can necessarily put our hands on, but it is directly relevant to the reason the point was raised and then called into question. So if there are no examples forthcoming let's drop this point (just so we're clear, that's not a request).

Originally Posted by Smokin

Source: Materials for Permanent Painting by DR. Maximillion Toch, uncle of Ralph Mayer, a scientist specializing in the chemistry of paints. Ch.21 The Failure of Sir Joshua Reynold's Paintings included his observations of Rembrandt's and Hals works.

That book was published in 1911; I'd want to read some current/more recent info in support of any factual statements. There have been strides in our understanding of certain things over the years (like the apparent lack of resins in Rembrandt works, despite the widespread belief in the early-20th century that they would be present).

Originally Posted by Smokin

Historical data is relevant...

It's certainly of interest to show what they believed to be the case at that time. But it's only relevant in support of a claim of lightfastness if it's accurate. That's all I was getting at, it wasn't a sophism just to score points. Again, also the reason I wanted examples of historical use where we know the colour is not down to later retouching.

Originally Posted by Smokin

Funny, Ive posted links that clearly showed ASTM ratings that varied from 1-4
from various manufacturers for PR83 (Not just the one from OH ).

Sorry, where?

Originally Posted by Smokin

Clearly, you are dismissing any information that contradicts the one you decided as true.

Firstly, that's the ASTM's own rating Frank, not something I "decided" on. Second, the supporting evidence that PR83 is not lightfast - in normal, everyday applications - is overwhelming, so the burden of proof therefore is on anyone that claims the opposite. To be as specific as possible: this isn't a question of lightfast enough (subjective) it's whether it's actually lightfast (objective).

Subjective - it lasts well enough FOR ME
Objective - will it fade with exposure to X amount of light

Originally Posted by Smokin

You said alot there I couldn't understand.

In all seriousness, which part of this is hard to understand???

Lightfastness is not a rating of a pigment when used only in certain ways, it is a measure of a pigment's total performance. What makes this so important in this case is that many painters want to use a crimson paint in exactly the ways that it's most at risk - in tints with white and in light glazes. In either case it can eventually bleach to nothing (literally vanishing).

Originally Posted by Smokin

I said that if you add a pigment that is known to cause a pigment to fade and become fugitive, then that has nothing to do with light fastness. I don't know what you find confusing about that.

I'm confused that you find it hard to grasp that the white is "merely an avenue to showing up the weakness that is already present (just as a glaze test does...)"

I'm going to quote Brian here, since he just addressed a similar point in another thread:

Originally Posted by Brian Firth

Accelerated lightfast tests using the direct rays of the sun are an accepted means of determining lightfastness in artists paints by the ASTM, as well as being a method in use for over 100 years. So, yes they are valid. If you do not believe it to be, then you should take up this issue with the American Society for Testing and Materials.

This includes the issue of tints with white. We don't need to waste any more time in this thread on debating whether a pigment should or should not be tested this way or in thinner glazes, it should seem perfectly reasonable given they're a normal use for a pigment.

Einion

[Einion]

This thread is about an issue of lightfastness, not permanence (a much wider issue with dozens of possible factors, none of which may be relevant here). If anyone wishes to delve into that issue further then start a new thread on lightfastness/permanence factors, testing etc.

Einion

[Daniel_OB]

Einion
"That book was published in 1911; I'd want to read some current/more recent info in support of any factual statements..."

Many books made "a long ago" are by no means inferior to nowadays books. I think it is just opposite (with no many exceptions). Just one example: Janson, History of art (arond 20 yars ago made is much better than last eddition revised by some modern guys).
The one example more, out od art:
GM, DSX (Chrysl.), and Ford design departments, and their suppliers also, employ one low paid engineer and attach to him (in average) 3 students searcing google for problems solutions "engineer" deliver to them. When he "think" he got solution for the design, he make sketches and e-mail it to India where "some" guys make final design with CAD. Look where American cars are today. They are full of stripped bolts (knowing you here is evidence: "Stackpole" vane X22F pumps for GM cars). It is modern knowledge and digital days. Fortunatelly there are still guys walking to libraries. Do not overbeleive in digital guys, they are most of the time quite stupid.

[Smokin]

Well, I was starting to respond in the typical manner that Enion likes, take this sentence respond, then take another sentence and respond. I’m not going to do that this time as I just don’t think that helps anything. I took a look at my first post to this thread and I actually said all I wanted to in that one post. Why all that tit for tat responses in an unproductive way, I don’t know, very few good questions or fair concerns/points came from it, rather it seemed to me it was a way to undercut the information because it conflicted with certain assumptions.

[Smokin]

The issue of light fastness: I never suggested that alizarin would not fade in direct sunlight. I know alizarin will fade in direct sunlight, but I know it won’t fade in ambient light based on historical use of alizarin. Permanence and light fastness are two very different things and that’s always been my point, how a pigment fairs in a light fastness test will affect the overall permanence of a pigment of course. One person suggests that no alizarin seen today can’t be 500 years old because the light fastness proves that the inevitable conclusion is it will disappear. That is an assumption, not evidence. Direct sunlight is very different from ambient light and frankly I’m surprised that anyone assumes this. Light doesn’t get "banked". Take a damp cloth and stick it in direct sunlight, put another in a dimly lit room, one will get dark & moldy, one will get bleached and crisp. Two very different results from two very different environments. People get scared of getting skin cancer by tanning for too long, not by banking light rays to an "inevitable conclusion". Lightfastness test are designed to simulate what will happen in the long term in ambient light, but even the ASTM test clearly states that results may not reflect real world results.

As for adding white and questioning how homemade light fastness tests are done, I still haven’t seen anything that makes sense or that would make anything I said moot. Adding lead white, ochre, siennas and other metallic pigments will cause alizarin to lose its permanency. Doing a lightfast test on a pigment used in a way it shouldn’t be used in the first place, is not a fair way to assess a pigment’s light fastness.

[Brian Firth]

The ASTM lightfastness rating for a specific pigment in a specific medium does not change, it is set once determined. The variations in the ratings you have noted are mistakes by manufacturers or others who have incorrectly published wrong information, they are not reflective of changes or variations made by the ASTM. THE ASTM LIGHTFASTNESS RATING DOES NOT VARY. PR83 is rated ASTM Lightfast III oil and acrylic, period.