More oil on Canvas

 

More Oil on Canvas!

Hi David,

I read your answer to Esmie's question re: priming canvases in the latest edition of Art Avenue.  I went to Golden's website as you suggested but now I'm confused.  You state in your reply to coat the back of the canvas with GAC 400, and to put one or two coats of GAC 100 over the gesso on the front of the canvas.  On Golden's website they say that GAC 400 can be applied to the canvas to stiffen the support before gesso application but don't say that it should be applied to the back of the canvas, and they go on to say a two coat application of GAC 100 is recommended before applying gesso indicating that the GAC 100 is under the gesso while you said the GAC 100 is applied over the gesso. 

Currently I am applying two coats of gesso to my canvases but after reading your article I think I should take even more care to practice sound archival techniques.   I want to be sure that I'm doing it the best way possible and was wondering if you could clear this up for me.

Lesley

Hi Lesley,

Yes I can clear it up for you.  Esmie's question was about what to do with commercial ready made, primed canvas that already has a coat of gesso. 

In your case you are preparing your own canvas so you can follow the instructions on the Golden web site: the GAC 100 would go on the front of the canvas before the gesso. I prefer to apply the GAC 400 on the back because it gives the fabric added protection against environmental pollutants and moisture. 

Hello David,

Thank you for your recent advice in Art Avenue about oil painting on cotton canvas. My question is what do you recommend to prepare linen surfaces for oil painting? I have stretched linen over Masonite and over stretcher bars and have coated the front of the canvas with rabbit skin glue or Gamblin PVA (Polyvinyl Acetate) before applying an oil painting primer (Gamblin Oil Painting Ground). What do you think of these methods? Do you recommend others?

Thank you, John

Hi John,

The methods you describe are standard practice for preparing linen for oil painting and have been proven reliable by the test of time. 

The PVA is a modern, upgraded substitute for the traditional hide glue (often called 'rabbit skin' glue).  I say upgraded because it will not become brittle over time as the hide glue does. 

I would not hesitate to recommend the method I described for preparing cotton canvas, using Golden's GAC 100 and 400 mediums that is, for painting in oils.  And as anyone who has stretched both cotton and linen canvas will know, stretching cotton is easier than stretching linen.  Linen is much more expensive than cotton as well.  The method described above gives cotton all the desirable qualities that have traditionally made linen the fabric of choice for permanent painting in oils. 

As for attaching canvas to Masonite (hardboard) I am also comfortable using acrylic mediums and gesso for oils.  Because you are painting on a rigid surface the problem of the oils separating from the ground/fabric are not an issue as they would be with a flexible support (canvas). 

Dear David,

I read with interest your art techniques column (Sept-- Oct of Art Avenues) and have a further question. If you use a commercial canvas from the store and coat it with gesso and then coat it with acrylic paint will it be satisfactory to paint with oils on it?  I have painted for a long time and have not come across artists who are
using your method with the GAC unless I am unaware of it.
I would appreciate a reply.

Shirley

Hi Shirley,

You are right, I haven't come across any either.  Artists are not often taught about materials and techniques anymore. 

An extra coat of gesso and/or acrylic paint will help, but only marginally.  After the oil paint layer has dried it loses most of its flexibility.  If the canvas moves, flexes, expands and contracts, the gesso/acrylic paint, which stays flexible indefinitely, will move with the canvas and the dried oil paint layer will inevitably crack, separate from the acrylic paint or gesso layer, and lift.  Many artists use acrylic underpaintings for their oils and I recommend that this practice is best performed on a rigid surface instead of a flexible one like canvas. 

If you are already putting two layers on top of the already gessoed canvas before painting then I suggest that you follow the method outlined above.

Hi David,

I read your recent article in 'Art Avenue' with great interest.  You have provided answers to several questions that I had meant to ask you after your previous article.  I have another question related to this very topic:

Is it ‘safe’ and ‘useful’ to apply GAC 400 on the back of the
finished oil paintings?  I have painted many oil paintings without
following the detail recommendations you have raised in your article.

Tony

Hi Tony,

No, it is not safe.  The GAC mediums, like all acrylic mediums, are water based.  If you apply any acrylic medium to the back of the canvas the water will travel thru the canvas and may cause lifting of the oil painting.