Varnish canvas bourne art

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Dave

Dave

SPFG, Supreme Picture Framing God
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At Rebecca's request, I thought I'd begin a new thread regarding the advantages of varnishing paintings. I'll start it off with a quote from Jeff from the thread dealing with conservation of oils and whether glazing is the preferred treatment.

Jeff Rodier said:
Oil paintings still need to be varnished whether glazed or not.

...
Click to expand...

I'm only partially agree with you, Jeff. Oils in a controlled environment such as a frame don't necessarily "need" varnishing however I do feel that they call out for it.

Varnishing serves two purposes. One is that it affords a layer of protection of the pigments from from airborne pollution and dust and dirt The second is that the colors become more vibrant and the brushstrokes more pronounced, IMO, when a semigloss appropriate varnish is applied.

Normally most oil pigments will dry with varying degrees of sheen. Different pigments dry at different speeds and at different degrees of sheen. Applying a varnish, whether it is gloss, semigloss or matte provides an overall uniform look to the painting. Indeed one way to tell if a painting is varnished is to hold it to the light and see if it has this uniform sheen.

One of the most rewarding tasks I do in my shop is cleaning and varnishing paintings. I never attempt this unless the painting is in excellent shape and the adhesion of the pigments to the substrate is sound. Otherwise I refer the work or subcontract it to a qualified conservator.

Cleaning and re-varnishing a painting is a sensual experience that provides an intimate exposure to an artist's technique and style. It is usually a somewhat laborious process whereby you work on the painting only several square inches at a time. You really get to know how that artist worked.

Back to Jeff's comment... Colors and brush strokes are accentuated and the overall appearance of the painting is enhanced when it is varnished. Therefore, it is my opinion, that even if glazing a painting while framing it should be varnished.

One more point... I believe as framer's, we are the last line of defense to make sure art is properly preserved. It is our duty to be as well informed as possible in order to properly advise customers about preservation. This includes varnishing oils. Most artists now-a-days will readily sell a painting before the 6-12 months have passed and, more often than not, will fail to inform their customer that the oil painting should be varnished. If we do not inform them prior to framing then we are doing a disservice to our clientele.
 
I agree with what Dave said.....
 
Jeff's comment caught my eye, too.

There may be aesthetic reasons to varnish, as that coating may be used to modify the surface texture of the artwork, but I don't understand about the "need" to varnish a painting protected in the almost-micro-environment of a closed frame.

Jeff, what would be the "need" of varnishing a painting that would never get dirty?
 
Thanks for starting this thread!

How long does an oil painting need to dry (min-max) before applying varnish? A year?

Dave, do you also varnish acrylic paintings? Would that help in any way, eliminating the sensitivity of dirt getting trapped into the little 'air holes' when acrylic dries?

I think I will start using some varnish on my own paintings, and see how it goes. It might be a service I would like to add as well.

How do you charge?
 
Most oils will dry enough in 6-12 months to varnish. Some heavily painted impasto paintings may take much longer. Oils never really completely dry as the drying process involves both the interaction of oxygen with their binder and the evaporation of the solvents use. This is a continual process.

I use to routinely varnish acrylic paintings but have been re-thinking that. Acrylic paint dries by evaporation of the solvent, usually water.
This is a quick process however there are also tiny holes in the paint surface which can attract and lodge dirt.

Here's an excerpt from this site: http://www.si.edu/MCI/english/learn_more/taking_care/acrylic_paintings.html

Removal of the top most dirt layer is perceived to be easier on a varnished painting. Unfortunately, varnishing an acrylic painting is problematic because the dried acrylic paint layer is soluble in the solvents used to make most resin solutions. Cleaning an emulsion paint with no varnish is also problematic because water may remove water-soluble additives and could make the pigment/polymer-binder interface less intimate causing colors to appear less saturated. Cleaning may also swell the thickener additives, disturbing the paint layer. Presently, there is no completely acceptable resolution to the problem of cleaning acrylic paintings.

It appears that it is even more necessary to glaze acrylic paintings and not varnish them than oil paintings.

Varnishing a painting is a relatively easy process. I usually charge about $ 35.00- 50.00 for varnishing a clean 16X20 canvas. Some say I'm too cheap but I'm satisfied with that amount especially if I'm framing the piece. My preferred varnish is W/N's Conserv-Art varnish mixed 2/3 gloss and 1/3 matte to produce a semi-gloss varnish. It is soluble with mineral spirits. Future cleaning is easy because you can clean the painting with mineral spirits or turp which is not as invasive to the painting as many chemicals needed to dissolve other varnishes.

Cleaning a painting is a different story and depends on the condition of the painting. Cleaning a painting requires the removal of the existing varnish and is quite laborious using various solutions depending on the varnish used. Much damage can be done to a painting by unskilled cleaning and it is best left to someone with experience and/or training.
 
I thought that varnishing oils was more pragmatic that aesthetic. The recent exhaustive and expensive treatments of Demoiselles D'Avignon to clean it because Pablo didn't like the look of varnish is a case in point.

I was taught that the varnish was applied (other than for aesthetics) to retard the natural oxidation and drying processes after the pigments had reached a stable state. Glazing may effectively provide the same benefits.
There is probably some historical basis for varnishing that covers the perceived need to regularly clean the paintings because of the deposit of soot on the paintings from open hearth fires, kitchen cooking fires and heavy oil torches that were used to illuminate (then there was all that tobacco smoke thanks to Sir Walter Raleigh). A coat of varnish would have been much easier to remove and replace that having to remove the smoke particulates from the pigment surface.
 
I wouldn't try to clean a customer's painting. The part on acrylic painting is very interesting. Better to stay away from the varnish there.
Thanks again, Dave, gave me lots of food for thought.
 
Dave,

I did not know that about acrylic paintings. Did they mention the acrylic painting varnishes, made from the same binders as the paint? I'm assuming from what they are saying, it would be a problem as well. I thought acrylics dried and changed chemically when dry.?

I use them for some frame finishes; they are tough as .... to remove.
 
Dave said:
I use to routinely varnish acrylic paintings but have been re-thinking that. Acrylic paint dries by evaporation of the solvent, usually water.
This is a quick process however there are also tiny holes in the paint surface which can attract and lodge dirt.

Here's an excerpt from this site: http://www.si.edu/MCI/english/learn_more/taking_care/acrylic_paintings.html

Removal of the top most dirt layer is perceived to be easier on a varnished painting. Unfortunately, varnishing an acrylic painting is problematic because the dried acrylic paint layer is soluble in the solvents used to make most resin solutions. Cleaning an emulsion paint with no varnish is also problematic because water may remove water-soluble additives and could make the pigment/polymer-binder interface less intimate causing colors to appear less saturated. Cleaning may also swell the thickener additives, disturbing the paint layer. Presently, there is no completely acceptable resolution to the problem of cleaning acrylic paintings.
Click to expand...

Turns out, that is exactly the reason it's recommended to varnish an acrylic painting first with a water base "isolation" coat of varnish & finish with a solvent based acrylic varnish coat.
 
There are two types of varnishing. As mentioned before, artists will use varinish to even out surface gloss. Different painters have different techniques. It depends how they mix their paints. Heavy on the solvent produces a matt finish. More oil more gloss. This is Retouching varnish and serves only a cosmetic purpose. It is also soluable with turps when dry. The 'hard' varnishes are intended more for protection and should only be applied once the paint has reached a certain stage of curing. Six-months is an oft quoted time, but maybe a year is safer on heavy paint. Varnishing too soon will allow the varnish to chemically bond with the paint rather than just sitting on top, so future removal is difficult if not impossible.

What should be avoided at all cost is using water-based varnishes. They are virtually bullet-proof when dry and resist even strong solvents. They also seen to absorb gunk from the atmosphere and darken.
This from someone who patiently scraped a coat of the foul stuff from a 36x24 canvas over a period of six years. :faintthud:
 
And this is why I am so glad I'm not a paintings conservator!

As we were taught in conservation school, emusions e.g. acrylic, pva etc. can have a very high concentration of binder molecule in the water solution (has to do with molecule polarity as I recall). So when a water based emulsion dries, the molecules are all tight and tangled up like spagetti. So they can be softened with solvent, but not solubilized. It's not a cross-linking thing, it is a physicle mesh kind of thing.

Organic solvent solution of acrylic or other binders can't get the same molecular concentration, so when they dry the molecules are not as tangled up together. So theoretically they can be resolubilized with the appropriate solvent. With aging or through chemical engineering, cross-linking can occur (chemical bonds between molecules) and resolubilization becomes problematic and sometimes impossible.

The problem with applying a water based isolation coat of varnish to an acrylic painting is that water can affect the look etc. of the underlying acrylic, so 1) application can change things and 2) if it ever needs to be removed, the process could change the structure/appearance of the underlying acrylic paint.

Glazing starts to look pretty good ; ) Especially for those pesky field of color paintings.

From my own terms of reference, artists have ideas and are allowed to do whatever they want, even if the results are unintended. It is their call whether a painting is to be varnished or not; with luck their decisions are based somewhat on materials science.

It is the caretaker's job to keep things as stable and unaltered as possible with the least amount of intervention possible. Ideally.

I think preventive solutions like environmental controls. whether they be macro or micro, are safest, but artist's intentions, cultural requirements/norms etc. need to be taken into account too.
 
From the painter`s perspective.... I clearcoat EVERY painting,regardless of medium.Generally with minwax polycrylic for works on heavy surfaces,and a thin spit coat of spray gloss on thinner substrates. i just like how the clear topcoat makes the colors"develop",they get much sharper,and more alive looking.Also,any work done with prismacolor pencils gets a spray coat.They are wax based pencils,and the art will develop a hazy white "bloom",over time that must be buffed away(at least it does that here...). Just wish I could remeber to clearcoat AFTER the scan,less digital clean-up,arrrgg!:shrug: L.
 
Lud!

Worked for many years in prismacolor pencils, doing my comic book/graphic novel thingey Night's Children (shameless plug!) The white bloom is the oxidation of the WAX in the pencils. Though you--I--wipe away that bloom after a week or so, I don't know how long those pencils "bloom." Or stop blooming. Spraying them with a fixative coating, I think, will not prevent them from blooming. It may be a Ticking Time Bomb as to when the painting will "blossom." And then nothing will save them from deterioration.

2 cents.
Wendy
The Art Corner
Salem, MA
 
wendy lang said:
Lud! Worked for many years in prismacolor pencils, doing my comic book/graphic novel thingey Night's Children (shameless plug!) The white bloom is the oxidation of the WAX in the pencils. Though you--I--wipe away that bloom after a week or so, I don't know how long those pencils "bloom." Or stop blooming. Spraying them with a fixative coating, I think, will not prevent them from blooming. It may be a Ticking Time Bomb as to when the painting will "blossom." And then nothing will save them from deterioration. 2 cents. Wendy The Art Corner Salem, MA
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I generally leave em alone until they look a bit frosty,then buff em with a soft cloth (old t-shirts...ligt colored totally rock here)...then I shoot em with a light coat of spray clearcoat. Hasn't backfired yet...20 + years. That said...I would never put anything on some one else's work...ever! L.
 
Rebecca has brought up a very interesting point in this debate.

We are framers, not conservators or artists. We cannot know exactly what media an artist has used and, therefore, are largely guessing what varnish/sealer/etc to use with it. If we get it wrong the resulting disaster may well unfold months, even years later but it will be our fault.

I would hesitate to apply any finish to a customer's artwork.
 
Here's an excerpt from Winsor & Newton's website:

10. Why should an Acrylic painting be varnished? As the acrylic film approaches its final dry state, the last few evaporating water molecules leave micro-pores in the film. These pores cause the film to feel tacky, even when fully dry. The micro-pores remain open indefinitely, meaning that the porous acrylic film can freely accumulate dust, grime, and smoke from the atmosphere. While that grime may not seem to be much over a week or a month, it adds up over the course of years. The best way to protect the painted acrylic film is to varnish. Winsor and Newton produce a range of acrylic varnishes.
For further information on acrylic varnishes click here.



It appears W/N still recommends varnishing acrylic paintings.


More information on varnishing oils and acrylics can be found on their website here:


http://www.winsornewton.com/main.aspx?PageID=406#o11

This site also includes information on removing both oil and acrylic painting varnishes.
 
Ylva said:
Hmmmm, if W/N would start selling glass, they would promote glazing....
Click to expand...

I was kinda thinkin' that too, Ylva.

;)
 
While working for a conservator we handled paintings on a daily basis and the most common damage was checking. Checking for those who aren't familiar is the cracks that develop throughout the painting over time. The most common cause of checking is environmental though some comes from paint used throughout the centuries by starving artist that could not afford the best.

My experience is with paintings going back nearly 900 years. Unvarnished paintings nearly always experience checking at some point in time because the environmet is not controlled. We as framers are not working for museums very often if ever. When working with museums we follow there set of criteria to a tee. Most paintings will travel through many hands, attics and garages glazed or not. I would guess that less than 1/1000 of one percent of paintings are handled, displayed and stored properly.

I have never seen one bit of harm done by properly varnishing paintings and the paint has a richness and depth that will never be seen without the varnish. Varnish is the easiest way to protect the paint surface for general viewing. Another advantage is that the varnish will be removed and reapplied periodically and at that time an in depth inspection will be performed. All of the customers that we handled oils for in conservation and general framing were called in once a year for a free reinspection.

A simple punture is a much easier and less invasive restoration than checking. Checking can become tens of thousands of dollars in restoration versus a few hundred for puntures.

The conservator I learned from was a Rocket Scientist. Literally he was the guy reponsible for getting the space shuttles into space and back on the ground safely. I state this so those here will understand the level of genious this man posessed.

The acrylic conundrum has existed for as long as the acrylics have been in use. Cleaning an acrylic has always been a horrific experience. His rule was that once one had been varnished it should always be revarnished. His rule for unvarnished acrylics was its a carp shoot. Acrylics of exceptional value recieved OP3 and no varnish. Acrylics of nominal value were assesed on a case by case basis with so many variables that you could not go into here.

We have no control over the viewing environment once the piece has left the store. Varnish has been proven protection for many centuries. The only thing I can say is that If I had a multi-million dollar painting, regardless of whether there was glazing or not there would always be varnish. I have seen 500 year old paintings in pristine condition with varnish and many more just 5 years old without that looked 500 years old with no varnish.
 
Well said, Jeff.
 
Jeff,

What Dave said, though,

traditionally, egg tempera paintings have not been varnished, and are very durable once dry. The even sheen on an unvarnished tempera painting comes from soft polishing. Varnishing one changes the optical quality and can, over time, with a traditional varnish, radically alter the color of some pigments. This has, I believe, to do with the "leanness" of the medium, oils being much "fatter".

In the transition from tempera to oils, certain pigments lost favor due to the different binders.

This is not to say an egg tempera should never be varnished, just that it should be done on an individual basis, being aware of the potential changes.

I do not varnish my egg tempera paintings.
 
Baer Charlton said:
How "near" and what was the substrate?

and just so you know that I take this question and information very seriously.. note that I'm blowing my 13,000th post on it.
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Best data at the time put it from 870-880 years old. Linen and relined on linen with beeswax. One year of restoration and in painting. 6 month dry time then varnished and another 6 months prior to going into the frame. Restoration cost was well above $50,000.

Another interesting restoration was a 450 year old South American painting on a Burlap Coffee Bean Sack. Had been found rolled in the attic of a 150 year old home and no family member ever recalled it being in a frame. A seam of the burlap ran vertically down the painting about 1/3 the way in the painting. We created a honeycomb aluminum substrate with a gap running down the seam position so it could remain flat. No way of stretching the painting since the burlap was of that age.
 
Baer Charlton said:
do you have any data on it's origin?
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Unfortunately Baer I was a kid at the time (about 20 years old) and these paintings were everywhere in the shop. Many came from overseas and were restored and then shipped away. I was excited about things I recognized the artist so many of the truly valuable items got no notice from me because I could not discuss the artists with friends. I really wish I had journaled my experiences but hey I was a kid.

It was an incredible experience since the conservator was a scientist. Every item that came in the shop was tested a hundred different ways. He was not satisfied with manufacturers claims so he used chemical tests and examination under a microscope. I was given specific tasks including tests but my results were never relied upon for decision making but rather a learning experience for my own benefit. He drove me nuts testing every board (mats), moulding, and even ran spectral testing on glazing choices. He had exposed to me the shortcomings of Denglas long before anybody knew the claims were quite optimistic. Uneven coatings and varying UV protection from one light to the next. Denglas was sold for appearance and not protection. OP3 was the only glazing trusted to deliver UV protection.
 
Just curious Jeff.

I like curiosities and would love to know where the practice of stretched canvas (which would denote some kind of use of a cassetta frame) predated the first known independent icon (carved from whole wood) by almost 200 years and the Italian use of the applied cassetta laid on wood plates by 275 and rabbeted cassetta by 300 years.

Back to the library I go
 
The artist was known for painting on commonly available and discarded surfaces. The fabric was most likely tacked to the wall during the painting process. Starving artist that never gained notoriaty. Most work did not survive since it was painted on remnants of any paintable surface. Over the centuries when canvas painting became the norm the piece had been mounted to stretched canvas. The painting had been through numerous repairs and had suffered extensive damage. Pieces were missing but over the years repairs had included a lot of in painting. Most missing images had clearly definable images which may have been interpretations in previous restorations. One section was completely missing the upper body and face of a person. Maybe a 3 sqaure inch segment.

The last major restoration had been performed in the early 1900's. Animal hide glue had been used in the relining of the painting at that time. The painting was then stretched on fresh bars of the time and the canvas was trimmed flush with the bars. There was eveidence of several repairs subsequent to that restoration. The painting had tears puntures and a couple of missing sections of paint.

When the painting was removed from the previous lining there were sections of the painting which were completely gone.
 
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