Portrait Artist Forum    

Go Back   Portrait Artist Forum > Paints, Mediums, Brushes & Grounds


Reply
 
Topic Tools Display Modes
Old 11-19-2008, 10:04 PM   #1
Jennifer Bogartz Jennifer Bogartz is offline
Juried Member
 
Joined: Jul 2008
Location: Portland, OR
Posts: 39
Final varnish




Is it absolutely necessary to varnish a painting once it is finished? What happens to an oil painting if it isn't varnished? I have some oil paintings on canvas that are several years old and have never been varnished. Do I need to clean the paintings before I varnish them? I live in Portland, Oregon where it is very humid, will this effect a final varnish layer? Thank you for any information you may have!
  Reply With Quote
Old 11-19-2008, 11:39 PM   #2
Claudemir Bonfim Claudemir Bonfim is offline
Juried Member
PT Professional
 
Claudemir Bonfim's Avatar
 
Joined: May 2004
Location: Piracicaba, Brazil
Posts: 1,042
Send a message via MSN to Claudemir Bonfim
Well, I noticed no one has answered your question yet, so I decided to give my two cents.

There are several reasons to varnish a painting, I specially like the effect, but the main reason is the protection. Dust, or any other undesirable thing, will stick directly to the paint if you don't varnish it. It will also be a lot easier to clean a varnished painting than an unvarnished one.

Some artists don't know, but oil paint never dries, it solidifies with the addition of oxygen molecules, and that's why the paint yellows with time. If the painting is varnished, then this process slows down a lot because the varnish yellows first (the Oxygen molecules cannot reach the paint easily) and can be supplied by new coats of varnish.
That's a tough job too, Mona Lisa lost the eyebrows during a process of old varnish removal.

Avoid organic varnishes!

Precious Paintings in museums receive very thick coats of varnish.

And yes, you have to carefully clean your painting before varnishing it.

Hope it helps.

All the best.
__________________
Bonfim
cmbonfim@gmail.com
  Reply With Quote
Old 11-19-2008, 11:46 PM   #3
Claudemir Bonfim Claudemir Bonfim is offline
Juried Member
PT Professional
 
Claudemir Bonfim's Avatar
 
Joined: May 2004
Location: Piracicaba, Brazil
Posts: 1,042
Send a message via MSN to Claudemir Bonfim
Ps.

After writing my reply I found this link
http://en.wikipedia.org/wiki/Varnish

I think it might be helpful.
__________________
Bonfim
cmbonfim@gmail.com
  Reply With Quote
Old 11-20-2008, 01:48 AM   #4
Marcus Lim Marcus Lim is offline
Juried Member
Finalist, Int'l Salon 2006
 
Marcus Lim's Avatar
 
Joined: Feb 2004
Location: Singapore
Posts: 324
Send a message via ICQ to Marcus Lim
Time duration of finished work important in considering for varnishing

Hi,
I'd like to add that timing is also an important factor to varnishing a painting. It's a definite no-no if you put a final varnish when the painting is touch-try, or recently done. This is because while we think the painting is dry on the outside, the actual fact is the painting is still 'growing' inside the painting. Putting a final varnish too early, results in serious cracking problems for the painting - think Bruce Banner ripping his clothes off if when turning into a hulk...

So often it's recommended to varnish only at least 6 months' after the painting's done - more than 6 months for thicker, impasto-ed paintings.
__________________
Marcus Lim
Historian Painter, Singapore
Facebook Page
www.marcuslim.com
enquire@marcuslim.com
  Reply With Quote
Old 11-20-2008, 09:49 AM   #5
Claudemir Bonfim Claudemir Bonfim is offline
Juried Member
PT Professional
 
Claudemir Bonfim's Avatar
 
Joined: May 2004
Location: Piracicaba, Brazil
Posts: 1,042
Send a message via MSN to Claudemir Bonfim
Marcus is right. Now I use a retouch varnish when my paintings are finished. The final varnish is applied only after 6 months or later.
__________________
Bonfim
cmbonfim@gmail.com
  Reply With Quote
Old 03-01-2018, 05:36 AM   #6
Mark Branscum Mark Branscum is offline
Associate Member
 
Mark Branscum's Avatar
 
Joined: Sep 2002
Location: Broken Arrow, Oklahoma
Posts: 62
Quote:
Originally Posted by Claudemir Bonfim View Post
Marcus is right. Now I use a retouch varnish when my paintings are finished. The final varnish is applied only after 6 months or later.

Do you sell your paintings with the retouch varnish on them? If so, then what do you communicate to your clients about the need for a final varnish in the coming months?

As an Artist I find this subject to be most elusive it seems so anyway .... there are tutorials and or articles on every step of the life of a painting from start to finish. But what happens when its finished ..... I mean if its a portrait painting ... your client is going to want delivery of the painting sooner than later not leaving time for a final varnish .... so how do you all deal with that?

Mark
  Reply With Quote
Old 11-28-2008, 04:41 PM   #7
Richard Bingham Richard Bingham is offline
Juried Member
 
Joined: Jan 2006
Location: Blackfoot Id
Posts: 431
While responses to this thread contain a lot of good information, there are also a number of errors, misconceptions and suggestions which are not entirely sound if taken as unqualified advice.

At the risk of starting a flame war, I presume to address them on the basis of 50 years experience painting in oils, and dealing with a wide variety of paint materials of all types:

Quote:
Originally Posted by Claudemir Bonfim
. . . oil paint never dries, it solidifies with the addition of oxygen molecules, and that's why the paint yellows with time. If the painting is varnished, then . . . the varnish yellows first . . .

Avoid organic varnishes!

. . . Paintings in museums receive very thick coats of varnish . .
One problem in discussing materials and methods is first to define the terms. Most people understand paint to be "dry" when it can no longer be manipulated, lifted from the surface, or malleable when handled. Claudemir is correct to state that the process of oxidation continues in oil paint films for a long time. However, for the purpose of addressing the question of a "final varnish" for a painting, it is only necessary for a paint film to reach a state where free volatiles have evaporated. As further noted, the length of time for a painting to reach this condition depends upon the thickness of the films and also ambient conditions.

The ultimate yellowing of oil films is a chemical reaction which has nothing to do with the oxidation of polymerized oils and/or resins. Curiously, the nature of linseed oil paint films is to yellow and darken when deprived of ambient sunlight. Humidity exacerbates the yellowing process, which is readily demonstrated by the oil itself, even before being incorporated into paint; it becomes increasingly lighter when exposed to sunlight.

A painting stored in a dark, damp place may yellow very noticeably in a relatively short time. Exposed to normal room (sun)light, the yellowing will reverse. The oil films cease to be reversibly reactive when the paint film has reached a certain point in the aging process . . . usually several decades.

Yellowing of the varnish films is a process independent of reactions taking place within the painting. Many old paintings have been restored to a state nearing their original condition when multiple layers of varnishes applied through the centuries (and the dirt, dust and smoke they contained) were removed by conservators. The most famous example was when Rembrandt's painting "The Night Watch" was restored. It had been referred to by that popular name for a great many years, when in fact, it is a daylight scene. (proper title, "The Company of Frans Banning Cocq and Willem Van Ruytenburch )

All solvents, vehicles, oils and resins generally associated with oil painting are "organic" in the sense of the definition of "organic chemistry".

Modern conservation methods find the old practice of applying numerous heavy coatings of varnishes of various compositions anathema to preservation.

While the wikipedia link provided is a good general-knowledge overview of materials which the term "varnish" comprises, it has little or no practical application to the especiality of oil painting or the preservation of oil paintings. For that matter, linseed oil alone is, by definition, a varnish in itself!

Quote:
Originally Posted by Marcus Lim
. . . actual fact is the painting is still 'growing' inside the painting . . . varnish too early results in serious cracking problems . . . think Bruce Banner ripping his clothes off when turning into a hulk . . .
Marcus, the principle is correct, but you have it reversed. As paint films continue to dry and give up their volatiles, they shrink They do NOT "grow". Problems with cracking and crazing may be caused by violating the "fat over lean" principle when making the painting. If thin, faster drying (lean) layers are applied over heavier, slow-drying (fat) layers, the lean layer will shrink or embrittle over a soft layer which is not shrinking. Think of Bruce Banner watching the surface of a mud-hole crack in a net-pattern as it bakes in the sun!

Varnishing too soon may cause cracking, but a more likely result (for damar or mastic at least) will be that the varnish will become incorporated into the painting itself through the process of solvent transfer, negating the advisability of having a "final varnish" be a removable, protective layer.

Quote:
Originally Posted by Michael Georges
. . . I have varnished paintings that were more than 25 years old . . . used . . . good turpentine to wipe the whole painting down . . . I add a bit of wax medium to my varnish . . . more of a satin finish.
While a painting 25 years old could very likely suffer a wiping with turps (or any other solvent) without visible damage, most conservators would cringe at the thought. Usually, the first line of cleaning is to dab the painting surface with surgical cotton dampened in distilled water. Of course, extreme cases would require something more, but in general, it's not a good idea to wipe down any painting with solvents prior to varnishing.

Adding wax to a "final varnish" is questionable on a number of levels. First would be the question whether the varnish chosen and wax are compatible. Damar and pure beeswax is a compatible mixture. The problem is the result is a varnish that is malleable, attracts dirt in its own right, and is much softer than damar alone.

In choosing a material to use as a final varnish, two requirements are inviolable: 1. The varnish should provide protection 2. The varnish should remain indefinitely soluble in its parent solvent to enable its ready removal at a future date.

A better long-range tactic would be to apply a suitable material as a final varnish, and regardless of its composition or final glossiness, a satin finish may be readily achieved by the application of a wax layer that is not part of the varnish

Quote:
Originally Posted by Claudemir Bonfim
Some guys like Damar, I personally think that it yellows too fast, but other[s] . . . haven't experienced the same problem, I think tht's due to climate differences . . .
Here, Claudemir addresses a major problem we encounter in discussing materials and methods. The traditional materials of oil painting have always been open to the question of the nature of the source, and the quality of the material. Resins are especially problematic, as those commonly associated with oil painting (damar, copal, mastic); each is a generic term encompassing a wide range of similar species, each with quite different individual qualities and properties. Sometimes it depends where certain species are grown.

What works well for me in the dry, cool climate of the high desert US west may very well cause specific problems in the humidity of tropical Brazil ! This is why it is so necessary for painters to become intimately acquainted with their materials, and knowledgeable by running their own tests. It's fascinating how closely processes in the studio and the kitchen are related! About the relative quality of materials, I could never understand how anyone could dislike oysters . . . until I was served a "bad" one! Simlar considerations apply to the painting materials we prefer!

Quote:
Originally Posted by Jennifer Bogartz
. . . Why is it best to avoid organic varnishes like the one made out of egg white and salt?
Our modern "just run down to the store" culture primes us to be surprised at such a suggestion as using egg-white for varnish. Anyone who has left the dirty dishes in the sink overnight quickly realizes that a number of food-stuffs are very tenacious adhesives and coatings . . . In earlier times, folks were intimately acquainted with where their lunch came from, and readily observed how blood, milk, eggs, and a number of other "food" items could provide substance for "paints" of different types and applications.

If you have ever encountered the "beauty secret" of using egg-whites in a facial treatment (to eliminate wrinkles?) you can readily understand how using egg-white "varnish" on a painting might not be the best choice . . . shrinkage is extreme, the film is brittle, and although Claudemir refers to being able to remove it easily with water, I wonder . . . after all, eggs (the yolk) are the major ingredient in "egg tempera" . . . a paint choice that's far more stable and permanent than oils! (ever had your car "egged" ??)
  Reply With Quote
Old 11-28-2008, 07:28 PM   #8
Claudemir Bonfim Claudemir Bonfim is offline
Juried Member
PT Professional
 
Claudemir Bonfim's Avatar
 
Joined: May 2004
Location: Piracicaba, Brazil
Posts: 1,042
Send a message via MSN to Claudemir Bonfim
I was missing your comments here Richard.

I prefer to use a mix of gloss and mate varnish, what about you?


Ps. I have never had my car "egged".
__________________
Bonfim
cmbonfim@gmail.com
  Reply With Quote
Old 11-28-2008, 10:45 PM   #9
Richard Bingham Richard Bingham is offline
Juried Member
 
Joined: Jan 2006
Location: Blackfoot Id
Posts: 431
I'm awfully old-fashioned. I use a 6:4 mixture of damar and mastic, I make up the varhishes in the studio using good turpentine and the best quality resins at a 5# cut (proportions: five pounds of resin to a gallon of turpentine)

This mixture is easier to manipulate than damar alone. I apply the varnish with a 2" badger sash brush and "lay off" the surface with the tip of the brush as the varnish tacks up to eliminate a high gloss.

I've heard a lot of good things lately about Gamvar, which is a synthetic varnish (I believe methylacrylate resin). The resin is dissolved in mineral spirits, and is reported to remain dependably water clear over time, as well as readily removable in MS indefinitely. It sounds good, but I haven't tried it yet myself . . . mostly because I don't see a pressing need to replace a method I've found suitable. Those who have tried it report that it doesn't lend itself to manipulation in application, so what you see is what you get!

I'm glad you haven't been "egged" ! (Maybe vandals in Brazil have better sense?)
  Reply With Quote
Old 11-28-2008, 11:35 PM   #10
Jennifer Bogartz Jennifer Bogartz is offline
Juried Member
 
Joined: Jul 2008
Location: Portland, OR
Posts: 39
Richard, thank you very much for your insight. You mentioned that artists can run their own tests on materials. How would I go about testing the materials I'm using? I am currently using walnut oil, walnut/alkyd oil, and liquin as medium (not all at once). I've heard some negative things about alkyds and liquin such as delamination and have not worked with them long enough to see those kinds of problems in my work. I'm in the process of researching varnish and can see the benefit of testing the material before committing to it. Does an artist need to try many different mediums and varnishes in order to become well acquainted with them?
  Reply With Quote
Reply


Currently Active Users Viewing this Topic: 1 (0 members and 1 guests)
 
Topic Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump

Similar Topics
Thread Topic Starter Forum Replies Last Post
Warning! Don't use damar as a final picture varish William Whitaker Paints, Mediums, Brushes & Grounds 48 06-23-2005 03:30 AM
Wax Varnish? Leslie Ficcaglia Paints, Mediums, Brushes & Grounds 0 05-24-2005 10:22 AM
Final varnish - matte or gloss Jeff Morrow Conservation & Restoration 33 01-09-2005 03:14 PM
Client framing vs. final varnish Terri Ficenec Framing the Portrait 4 04-27-2004 05:34 PM
Final Varnish Karin Wells Techniques, Tips, and Tools 4 04-24-2002 02:06 PM

 

Make a Donation



Support the Forum by making a donation or ordering on Amazon through our search or book links..







All times are GMT -4. The time now is 07:27 AM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.