Warning! Don't use damar as a final picture varish

[Virgil Elliott]

Originally Posted by Michele Rushworth

When I want to deliver a recently completed commission that has sunken-in dull areas, I "oil out" those parts of the painting with a 50% linseed/50% OMS mixture, rather than using any type of retouch varnish. That evens out the surface quite well and dries to a nice semi gloss finish.

Virgil, does this seem like a sound practice?

Michele,

Maybe. It depends on how much you leave on the surface, and on the percentage of oil there is in the paint making up the painting. If everything is right, the oiling-out oil will soon be absorbed into the paint layer, and become part of it. The painting should still be varnished after it has cured for six months to one year. If there are any heavy passages or impasto, one year would be better. I assume you always arrange to get the painting back for varnishing at the appropriate time. I make sure my portrait clients understand the importance of a final varnish, and agree to let me have the painting back a year after I've delivered it.

When oiling out, it's very important to wipe as much of the oil off as will come off, with a soft cloth, immediately after the oil is applied. Enough will remain on the surface of the painting to accomplish the purpose.

I hope that helps.

Virgil

[Michele Rushworth]

Thanks, Virgil!

[Tricia Migdoll]

What about the Amber medium? - and Amber Varnish.?

I did believe that amber was not a resin. Is this true.?

I certainly like using it.

[Scott Bartner]

I would also be interested in your opinion on amber medium and varnish Virgil. I guess Tricia is referring to the Blockx product, a very expensive darkish liquid packaged in a slender glass tube sealed with a cork and red sealing wax. It's a joy to get open.

One part amber medium is mixed with 5 parts cold pressed linseed oil. Very little of the amber is needed.

Unfortunately I was unable to experiment fully with this medium being allergic to solvents, but I know a few artists who swear by it.

[Virgil Elliott]

There are other mediums out there called amber mediums, which may or may not actually contain any amber resin, so unless I were to know which amber medium you're talking about, I can only make general comments. These all contain resin or balsam (coniferous tree sap), cooked oil and solvent. With Blockx, the oil is poppy oil and the solvent is spike oil, aka oil of aspic. There is another one by a small manufacturer that has a balsam and cooked oil in it, either walnut or linseed, a solvent (probably turpentine) and maybe some amber or copal resin in it, and there might be a few others out there with who-knows-what in them. The only one of these manufacturers whose word I would trust on what is in a product is Blockx.

Whether lots of people like to use a given medium or not is no indication whatsoever of its archival properties, nor is the apparent condition of the paintings in question when they are less than 100 years old. The people whose opinions I place greater credence in regarding these matters are the top museum conservators, who see and restore old oil paintings on a regular basis and are plugged into the international conservation community's information network. In that field, it is widely acknowledged that resins and balsams in old oil paintings are generally problematic, and that the oil paintings that have weathered the centuries best have no detectable resins in the paint layers.

Resins lack flexibility, and that is obviously a factor in the cracking of old paintings. One might or might not get by with a very minor addition of a resinous medium to one's paints, depending on many other factors. With a rigid panel support, the problems of cracking would be greatly reduced over paintings on stretched canvas.

Resins discolor, i.e., turn yellow and, eventually, brown. Bill Whitaker discovered this with his damar varnish. Once a resin has turned dark, it stays dark. It cannot be bleached back to its former appearance the way a yellowed linseed oil paint film can, by exposure to light.

Cooked oils are also looked upon as troublesome compared with unheated oils, as they are pre-oxidized (stand oil being the exception because it is cooked in an oxygen-free container).

Solvents also adversely affect the strength of oil paint films.

The mediums in question are composed of resin (and/or balsam), cooked oil, and solvent. There may or may not be driers added by the manufacturer, usually cooked into the oil, and that is another potentially problematic ingredient in the mixture, according to the best information I have come across in my studies on the subject and from my consultations with conservation experts at the National Gallery in Washington.

The 17th century artists who employed cooked oil mediums and/or cooked oil with balsam or resins only used these mediums for certain special effects in the final stages of the paintings, with most of the work done with paints composed of pigment and linseed oil, uncooked and with no resins or balsams in them. Walnut oil was sometimes used instead, but mostly it is linseed oil. It was not a matter of adding medium to all the paints, the way people love to do today. These paints were mulled to the desired painting consistency from dry pigments and unheated linseed oil, so there was no need to add anything to them. The Old Masters were not painting with modern tube colors.

In the mid-18th century is when painters began using exotic concoctions more extensively in their paints, and it is these paintings that have suffered more severe consequences as they have aged. Sir Joshua Reynolds is the poster boy for bad choices of materials, and it is probably his influence that made these concoctions popular in the first place. Reynolds's paintings are notorious in conservation circles for the many defects they have developed and for being among the most difficult to restore. Whereas the paintings of Rembrandt, a century or more older than Reynolds', have held up much better over the ages, with no resins in them. I think that is significant, and worth serious consideration.

Each painter can decide for himself/herself how important it is that the paintings he or she creates continue to look the way they look when they paint them, and how far into the future this matters. If one cares, it is probably better to leave the resins out of the paint. If one doesn't care about the future, it doesn't matter what one uses.

Virgil Elliott

[Virgil Elliott]

Originally Posted by Tricia Migdoll

What about the Amber medium? - and Amber Varnish.?

I did believe that amber was not a resin. Is this true.?

I certainly like using it.

Tricia,

Amber is indeed a resin. It is a fossil resin because it is very old. It started out as tree sap.

Virgil Elliott

[Valentino Radman]

I hope I won't sound too knowledgeable if I say that it seems that artistic community knew little about the drawbacks of using dammar up until the 90

[Michele Rushworth]

Virgil, thanks for sharing your expertise with us here. Your contributions are very helpful!

[Allan Rahbek]

Virgil,
I would also like to thank you for sharing your expertise.

Is there any alternative to this Gamvar Varnish?

Are you familiar with the use of Egg White for varnishing ?

Allan

[Mike McCarty]

I have had good luck (at least within my short artistic life, and in the practical application sense) with this product:

Liquitex Soluvar low viscosity, final picture varnish (matte finish)

and

Liquitex Soluvar final picture varnish (satin finish)

I mix these two products in a 50-50 mixture to attain the degree of matte finish that I like.

The label states that this product is "Pure acrylic spirit varnish."

The label also indicates that it may be diluted with a 25% mixture of mineral spirits or turpentine.

I'm not real sure where this falls in the above discussion. Surely this Gamvar can't be the only acceptable picture varnish.