Varnish
 

I want to layer my work as Norman Rockwell did by varnishing over the under paintings. I tryed Damar varnish and it dissolved with the next layer's application. I read in Norman's book that he used french retouch which dried quick and did not lift when painted over. Anyone know if damar retouch is different than french retouch varnish? If that question is outdated/obsolete what should I use for this purpose of sealing an underpainting?

Try using Liquin by Winsor Newton. It is an alkyd, will dry quick, and will not be removed by mediums or paint. I don't do much glazing, but I do use Liquin to rewet a dry paint area so that I can regain the wet-into-wet look. I also use it to eliminate the blonding effect of dry paint. I think I can safely assume Rockwell would have been thrilled to have Liquin. Windsor & Newton does not recommend Liquin being used as a final varnish, but I know a few painters who use it for that.

Varnish
 

Dear Valerie,

The "French" varnish Rockwell used was "Virbert Retouch Varnish". In the mid 60's the company which had bought the rights to Vibert's name changed the formula from dammar to a synthetic. A great product was destroyed. It is very nasty stuff to work over. I remember one of my old teachers was very upset about it.

Something comparable can be made by dissolving dammar tears in turpentine or mineral spirits depending on which you use for a thinner and as a component in your medium. One or the other throughout. One can order 100g of dammar from Kremer. Suspend it in a cheese cloth bag held by a string through a hole in the lid of a jar containing 200ml solvent. It should dissolve in up to five days. Make sure the jar is absolutely clean. Remove the bag and decant the varnish into a new jar. It can be used as such as a component in a medium or thinned 3:4 with solvent for retouch. It is up to you to select the best solvent. I use W/N turpentine with mastic rather than dammar.

One can simply buy dammar or mastic 1:2 in turpentine from Kremer and thin 3 pt with 4 pt turpentine. Dammar will dissolve in turpentine or mineral spirits, mastic only in turpentine in which it should be allowed to sit for three weeks. Stick with one or the other on the same canvas.

A 1:3 solution can be used as a final varnish a year or two later.

Varnish
 

I need to modify a background on a portrait that I have spayed a thin coat of retouch varnish onto. Is it safe to paint right onto this coat of dried retouch varnish or do I need to remove it (!) somehow?

A thin coat of retouch varnish isn't going to destabilize your work. I will often tone my white acrylic primed canvas using straight damar as a medium, then paint onto that. I have had no problems, and I have known many other painters who do the same.

Prep for final varnish
 

Occasionally clients do not return paintings for a final varnish within the 6 month recommendation and enough time elapses to warrant cleaning of the canvas as a first step. Usually dust is all that needs to be removed but currently I am faced with cleaning a 4 year old painting that has hung in a restaurant lounge where smoking is permitted and I am not sure what I should use that is aggressive enough to clean the painting but not risk damage. Thanks in advance for any advice.

To clean a dirty painting
 

If the paint is not cracked or flaky, try a few drops of mild detergent (Dawn) in a pint of warm water. I have used this solution to successfully clean some old paintings...be gentle and use a soft cloth.

After the surface is clean and dry you can recoat with varnish. I like Windsor-Newton's Conserv Art Gloss Varnish. Sometimes I just use Liquin.

Varnish
 

Dear Karin,

Oil based mediums, particularly those with a hard resin and those loaded with driers like Liquin, are unsuitable as a final varnish. They will darken and cannot be removed without damage to the painting.

Only soft resins in solvents for picture varnish.

Liquin vs varnish
 

So, if I use Liquin as a medium, most especially as a glaze medium, is it going to darken my painting inside the layers? The bottle says "non-yellowing..."

Varnish
 

Dear Karin,

Do you always believe what you read on labels?

Liquin is just an oil cooked with lots of driers and an artificial resin. It is not a miracle, and it lacks the handling qualities of traditional materials.

If you want to try the real stuff contact Jim Groves. I posted his address on this forum.

Paul

...believe what you read on labels?
 

Excuse me, but why not? Windsor Newton has been around a long time and has a very good reputation. I've been using Liquin for years and have NEVER had a problem with it. I understand that some people don't like the way it handles, but I can paint rather well with it. Yellowing and cracking is just not a problem.

Varnish
 

Dear Karin,

I was merely recommending superior products to a colleague.
In whatever claims, however fanciful, that may be made about this stuff no one recommends that a hard oil varnish should be employed where a soft resin in a sovent is appropriate. Both will eventually darken. The later can be removed with less chance of spoiling the painting.

Paul

Varnish
 

Dear Karin,

I just looked at my bottle of Liquin. The label reads: "Good resistance to yellowing."

This bottle was priced at $6.25 for 75ml. Good copal or amber varnish will run from about $40.00 to about $700.00 depending from whom one purchaces them for the same volume. Speaks volumes?

Alkyd resins, undiluted with additional oil or solvent, are priced at $4.00 for 75 ml at Kremer. Their alkyd mediums are $4.00.

Paul