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LDianeJohnson
07-17-2001, 06:15 PM
For a long time I have searched for viridian in acrylic. No go.

I was recently in a Sennelier art store in France and learned a little something. No viridian in acrylic...anywhere...in any brand.

Some of you may be able to shed more light on this. But as it was explained to me, viridian can be found in watercolors and oils but not acrylics due to its inherent inablilty to suspend in water. Watercolor binders somehow work with this pigment, but not successfully in acrylic.

So, as I have done for a long time, I'll continue to use substitutes or overlapping pigments to try and achieve as close a match as possible when needed.

Diane

cuttlefish
07-17-2001, 09:01 PM
To my knowledge, there isn't much water at all in watercolor paint. Only gum arabic or a similar binder. The water comes into it only to dissolve and dilute the paint and distribute it across the paper, where it evaporates rather quickly.

Acrylic paint as we usually encounter it is an emulsion. Water is present in the wet paint, which would preclude water unfriendly pigments like viridian from being used. The acrylic polymer chains are suspended among water molecules, sort of like wet spaghetti. When the water evaporates, the polymer chains become entangled amongst eachother.

Pigments in this analogy are sort of like sauce. Some kinds stick to the noodles and distribute evenly, others just flow to the bottom and won't mix in no matter how hard you try. Viridian strikes me as being in the latter category.

A good alternative to viridian is phthalocyanine green, yellow shade (PG 36). I've seen this color only in Golden acrylics, but I may have missed something else.

LDianeJohnson
07-18-2001, 09:24 AM
Thanks for your input!

Yes, I've found phthalocyanine green to be a good alternative as is Lascaux Green Deep.

Diane

jheinrich
07-18-2001, 10:34 AM
I too have looked for viridian for a long time- bummer that it doesn't exist.

Are there any other colors that you know you can get in wc or oil, but don't come in acrylic?

just curious ...

j*

VictoriaS
07-18-2001, 12:35 PM
Originally posted by jheinrich
Are there any other colors that you know you can get in wc or oil, but don't come in acrylic?

just curious ...

j*

Yes, I read something... could it have been prussian blue?? I'm not really sure, though. (So why do I say anything?) I can't remember what book I seem to recall reading this in, but I'll try to find it.

Einion
07-19-2001, 02:50 PM
Diane, sure enough, checking my information here and on the 'Net suggests that this is not offered as an acrylic by anyone. I am embarrassed to admit that the colour I have been using for years (very sparingly obviously!) that I assumed was Viridian must in fact be Phthalocyanine Green! This was bought long before PG7 or PG36 were actually offered as colours under their real names (yep, that long) and I have been blindly assuming it was what it said it was... now if only the tube hadnít given up the ghost ten years ago I would know who to blame!

I vaguely recall reading that it is not that it doesn't mix with water (there is water in some quantity in many if not all watercolours, an example: gum arabic, glycerine, dextrine, water) but I think there is a chemical reason that it is not made into acrylic, to do with the pH but I can't find any references on this. Viridian may be hydrophobic, but so are a number of other pigments; that's what wetting or dispersion agents are for. Ox gall for one is used in watercolours and there are others used in acrylics; simply adding detergent would probably work although you would have to use an anti-foaming agent (a common additive in acrylics anyway).

Er cuttlefish, Phthalocyanine Green is offered by probably all acrylic manufacturers! Off the top of my head I know Liquitex, Golden, W&N, Rowney, Maimeri, Da Vinci and Rembrandt offer it. Winsor & Newton apparently has the widest hue difference between the blue and yellow shades of any manufacturer, just like with the phthalo blues. BTW, I thought Viridian was a blue-green shade, wouldn't that make Phthalocyanine Green BS a closer match?

Jeanette, there are a quite a number of pigments never offered in acrylics, the reasons stated were twofold: firstly because they decided at the beginning to only offer the most lightfast pigments to go with the permanence of the medium, and second to have the most reliable palette where there were no pigments with possible chemical interactions - no lead compounds because of reaction with sulphur for example. I have also read that they deliberately avoided any pigments of the most toxic classes, so again no lead, and no mercury or arsenic but this may in fact relate to their reactivity and not to any high-minded ideal of protecting the public. We know that acrylic offers significantly less protection to pigment particles than oil does in many cases, which may explain a lot ;)

Victoria is correct, to the best of my knowledge genuine Prussian Blue is not offered by any acrylic manufacturer. You will find the name in a few ranges but it is a hue: Da Vinci offer it for example, although why anyone would want to pay good money for a simple mix of Phthalocyanine Blue and Lamp Black is beyond me! Phthalocyanine is similar in hue, plus being more lightfast than Prussian Blue and there may again be a chemical reason.

Einion

cuttlefish
07-20-2001, 06:20 AM
Originally posted by Einion
Er cuttlefish, Phthalocyanine Green is offered by probably all acrylic manufacturers! Off the top of my head I know Liquitex, Golden, W&N, Rowney, Maimeri, Da Vinci and Rembrandt offer it. Winsor & Newton apparently has the widest hue difference between the blue and yellow shades of any manufacturer, just like with the phthalo blues. BTW, I thought Viridian was a blue-green shade, wouldn't that make Phthalocyanine Green BS a closer match?
I know that all brands offer the blue shade, but Golden was the only one I was aware of that offered the yellow shade. Pardon my error.
In my experience, the yellow shade of Phthalocyanine Green still tends toward a cooler tone than other greens, with the exception of Phthalocyanine Green blue shade. It's been a while since I've seen true viridian; it's a cool green, but to my recollection not as blue as Phthalocyanine Green BS.

LarrySeiler
07-20-2001, 09:55 AM
This is most interesting.

I just purchased a Phthalo Green, looking for Virdian actually Diane...but not seeing it, I grabbed Phthalo.

Between the various yellows and blues, I ought to still get close to the landscape greens I'm after. We'll see....

Larry

StarGate
07-20-2001, 02:24 PM
I found this link that lists two ways to mix acrylics to get the Classical Virdian color - here:
http://www.goldenpaints.com/jp06art5.htm
and it also lists other classical colors.

Dima
07-20-2001, 04:30 PM
Hi Diane and others,

It is technically difficult to mix the viridian pigment well with the acrylic binder. Can't remember what the problem is exactly, but there is the reason you won't easily find viridian in acrylics.
However Golden did carry a viridian for a while, but they discontinued it.

Dick

Einion
07-20-2001, 07:31 PM
I have the same problem as you Cuttlefish, I haven't seen the real colour (that I can be sure of) for years so I have nothing to compare it to except reproductions in books which are obviously no help. Anyone have both genuine Viridian and one or both of the Phthalocyanine Greens so you can compare them for us?

Thanks for that info Dick, maybe the Viridian I have actually is Viridian after all (wishful thinking I know...) I should buy the two Phthalo greens and compare what I have to them I suppose :)

By the way I made a mistake in my last post, I was checking though my information and you can in fact get genuine Prussian Blue from Liquitex at least, so obviously it can be made into acrylic; I just checked their site and it is still in their lists. Funny thing is they list its Munsell hue as 9.2BP (blue-purple)... I thought it was a blue-green??? Help, anyone have some of this too?

Einion

LarrySeiler
07-21-2001, 07:38 PM
I check with Don Jusko on this matter, and he says the following-

[quote]"Oxide of Chromium Brilliant, hydrous green chromic oxide. I think Viridian hue mixes with a little yellow ocher and black in Thalo Green."[unquote]

I don't know...might be worth experimenting. I'll stick with phtalo green I suppose.

Larry

sarkana
07-22-2001, 10:06 AM
viridian is also becoming more rare in the world so i think that even in oil paints we will be seing less and less actual viridian. it is a beautiful color for which there is no real substitute. it is so much more subtle than any phthalo that i would hesitate to recommend it in place of viridian.

viridian is a semi-transparent emerald green. it is hydrated chromium hydroxide, Cr2(OH)2.

i suggest to all of you acrylic painters out there that you buy a little viridian pigment and experiment. if you mix it in to the emulsion and use it right away, the pigment won't have the opportunity to fall out of emulsion.

LDianeJohnson
07-26-2001, 05:55 PM
Thanks to all for your great insights and input on this subject!

mstownsend
08-01-2001, 05:01 PM
Viridian Green Pigment does not really like to be in a waterbased acrylic in terms of shelf life. Mixing the pigment into an acrylic and using it fairly quickly is the best method, but I doubt you'll see a true Viridian Green in a premade acrylic unless there is some breakthrough.

Real Prussian Blue is only made by Liquitex (in acrylics). Again, it's a matter of instability rather than compatability.

There are many pigments that react with the alkalinity of acrylics but do fine in acidic oils, and vice-versa.

Mike