Why won't my paint stick to certain areas of the canvas?

April 13, 2010 8:53 AM

Why won't my paint stick to certain areas of the canvas?

I've started painting with acrylic paints recently and noticed that there are little parts of every canvas I have used (which, granted, at this point is not many) where paint just does not take very well. Why is this? Cheap canvasses? Red seems to stick the least best and white the best, but, no matter what color, there are some spots where the paint just looks transparent and I cannot build it up.

I am not a very good painter and am not looking to spend a lot of money on supplies but I thought that I would see if anyone has a solution or at least an explanation for this.

posted by roxie5 to Media & Arts (8 answers total)

Gesso
posted by Perplexity at 8:58 AM on April 13, 2010

Best answer: You need to "size" the raw canvas before painting. Sometimes you can buy a sized canvas but typically it is not sized.
posted by JJ86 at 9:13 AM on April 13, 2010

Seconding Perplexity and JJ.

Also, you shouldn't expect all your acrylic colors to behave the same way on the canvas, or when mixing on the palette. Some pigments are just better at being opaque than others. Better brands of acrylic will have opacity and lightfastness information on the tube, or you can search for charts like this one from Golden Acrylic.
posted by alight at 9:15 AM on April 13, 2010

When you say it looks transparent, do you really mean transparent? Some paints are made to be somewhat transparent. Acrylics generally have a transparency rating on the label. This is a desirable effect when you know how to use it, but it's often useful to have a few different paints, like a red that's got a decent transparency and one that's really heavy and opaque.
posted by advicepig at 9:16 AM on April 13, 2010

I really (ashamedly) liked using Canvassette. It took paint more easily than real canvas and needed much less prepping (ie, none).
posted by thebazilist at 9:20 AM on April 13, 2010

Best answer: You're talking about a primed canvas right, pre=stretched, that you bought from an art supply store? Was it inexpensive? Probably lousy priming. There are a lot of poor quality art supplies which have flooded the market, and unfortunately quality (not necessarily same as price) really makes a huge difference in art supplies. The primer (for acrylics, gesso) is the white paint-like stuff that goes on the canvas first, before the paint. One of its functions is to create an even surface that acrylic paint will adhere to, so if the paint isn't sticking properly the gesso isn't doing its job well. To fix this you can buy some quality gesso and apply more of it and more evenly to the canvases you have. If you want more work for yourself in the future you could buy raw canvas and stretch and gesso it yourself, or you can buy the more expensive pre-primed canvases, like the better ones made by Fredrix. Another simple thing is to keep your hands off the primed canvas, as oils from your skin will absorb into the primer and repel the wet acrylic.

If you're talking about raw canvas than that's another thing entirely. Then you just have to prime it in the first place.
posted by tula at 9:26 AM on April 13, 2010

If the canvas is made of cotton, it will take a bit for the resin in the acrylic to wet it enough to stick if you don't prime it first. Dirt will also cause poor adhesion initially.

Cheaper brands of paint use lower quality resins and lower pigment loads resulting in reduced performance, and additional layers of application required to achieve a desirable effect.

Synthetic fiber brushes will work better with acrylic media.

If you overthin with water, your acrylic paint will be underbound, and the pigment will not adhere as well. If the dried paint film looks dull and powdery, you are undermining the binder and the pigment is out of dispersion.
posted by effluvia at 11:27 AM on April 13, 2010

reds are almost never opaque. it's because red is so close to infra-red on the spectrum...pick up a good book on painting, it will tell you what you can expect from various pigments. but generally, if you want something to be red red red, you generally have to paint that area white again first (or pink works), then paint it red...
posted by sexyrobot at 1:28 PM on April 13, 2010