Acrylic Odds and Ends

 

Acrylic problems

Hi David,

I took your Mastering Acrylics 1 & 2 workshops in Kelowna in 04. I have been using your advice as to mixing gloss medium with the paints to maintain integrity of the colors. Usually for the final coat I use just gloss medium.  I ran into a problem when I used one part matte medium and four parts gloss medium as you suggest, for the final coat.  The digital image that resulted had a milky, hazy effect and the colors were not true, especially the blues. I have spoken to other artists and they have noticed similar effects.  My question is, why does this happen?  How do you eliminate the unattractive gloss on an acrylic painting?

Problem 2. I have a canvas that had a failed acrylic painting that was subsequently covered with gesso and repainted on.  This new painting has begun to peel away from the canvas in spots and only after being dropped and bumped.  I have painted over gesso paintings before and so have other artists I know and this has never happened before.  Any ideas why?

Thanks,   Looking forward to hearing from you. Jeannine

 

Hi Jeannine,

Well now, let's see...

You say you use a final coat of just gloss medium on your paintings.  That is OK, and would be considered a layer of 'isolation' varnish.  For the picture varnish I mix 1 part matte to 4 parts gloss but I do NOT use acrylic mediums, I use an acrylic solution varnish like Golden MSA, or Liquitex Soluvar for the final picture varnish.  It sounds like you might be varnishing your paintings with acrylic mediums instead.  That would definitely be the reason for the milky appearance - these mediums are hard to brush on without ending up with a cloudy look, especially if the painting has texture. 

Also, always photograph your paintings before varnishing them.  Any raking light will show up as glare on the image and digital cameras are particularly sensitive to light source. 

Gesso does not have a lot of adhesive strength and will not stick well to an already painted surface.  It is meant to be used on an absorbent, porous surface with some 'tooth', like canvas, so that it can hold on with having to be too sticky.  If you want to cover over an old painting, use white paint first, not gesso. 

Hope that helps, have fun!  David

Dear Mr. Langevin,

I just finished reading your article discussing permanent supports. Here is my question: I want to paint on an unstretched large canvas which will ultimately hang like a tapestry on a wall (if you are familiar with May Stevens acrylic water paintings, she staples (yes, staples) them on the top right to the wall. The dimensions I am working with are 84" x 72". I am trying to decide whether to use cotton or linen canvas. I am painting with acrylics. Do you think cotton canvas would be as sturdy as linen if I coat the back with acrylic polymer? How would gravity affect the unstretched canvas on the wall over time? If you could answer these questions I would be most grateful.
 
Thank you for your article.

Best regards, Laurie

 

Hi Laurie,

Sounds like a neat idea.  I would use heavy cotton canvas, a least 12oz, for acrylic and I would coat it with Golden's GAC 400 medium on the back, probably two coats would be adequate.  The GAC 400 is a fabric stiffener that will help prevent the fabric from sagging under its own weight over time.  I would put a coat of acrylic medium on the front as well before painting.  This will help prevent sagging which is caused not only by gravity but by fluctuations is humidity.  The acrylic mediums will also make the canvas less absorbent for atmospheric moisture.