Acrylic Paint Problems

Troubleshoot Issues You Might Encounter When Painting With Acrylics

Art.
artisteer / Getty Images

Every artist encounters a painting snafu every now and again, but sometimes it's not you but the paint that's the problem. Check if the issue you're struggling with is on this list of acrylic paint problems, and learn how to rectify the situation.

Separating out in the Tube

If when you squeeze the acrylic paint out of the tube you get a worm of thick paint surrounded by a puddle of almost-clear liquid, then the paint has separated. The pigment and binder are no longer properly mixed together. It's not something you've caused; it probably went into the tube like this, the scrapings off the bottom of the barrel.

Solution: Live with it and mix the pigment/binder back together with a palette knife. Or contact the art store you bought it from for a replacement and, failing that, the manufacturer.

Paint Drying in Tube

If the paint you're squeezing out of a tube is stiff and thick, won't come out easily or comes out a bit lumpy (more like clotted cream than buttery), then it's probably started to dry within the tube. If you can still get it out the tube, it's still usable, but will take a bit of mixing with water and working with a painting knife to get the consistency you desire.

Solution: Ensure you put the cap back on the tube straight and tightened all the way. Do it timeously; don't leave a tube lying around open, especially in a hot environment. With plastic tubes, try to avoid getting air into the tube.

Not Covering What's Underneath

If you've painted a section and it hasn't covered up what's underneath it as you expected, check the colors you're using. It's highly likely you've been using transparent pigments rather than opaque.

Solution: Swap to opaque pigments, or mix in a bit of titanium white which is extremely opaque.

Color Shift From Wet to Dry

Depending on the brand of acrylics, and more so with cheaper paints than artist's quality, you may encounter a color shift from when the paint is wet to when it's dry. It may get darker as it dries. This can make mixing a color again to match tricky ​and make a painting turn out much darker than you'd intended.

Solution: Upgrade your paints to a better quality. Learn through experience how much a particular brand darkens, and learn how to compensate when color mixing.

Drying Too Fast

Most brands of acrylic paint are formulated to dry rapidly, but if conditions are right (or wrong?) you can find you can't even get the paint from your palette onto the canvas before it's dried.

Solution: Check if there's a draft across your canvas, whether from a window, fan, or air-conditioner, as this will speed up the drying time of acrylic paint. Use a fine-mist spray with water over your palette and canvas regularly, or mix in some retarder medium.

Not Drying At All

If you've mixed retarder with your acrylic paint and it's now not drying at all, you probably added too much. Check the label of the retarder to see what the recommended proportions are.

Solution: Try to remove as much of the paint that's not drying as possible.

Dried Paint Lifts

If you find that paint you thought was dried lifts off the canvas when you paint over it, chances are it didn't have sufficient binder in it and too much water.

Solution: Thin your paint with glazing medium not only water. Paint over the area gently with a layer of glazing medium to try to seal it without disturbing it too much.

Foaming Paint

Acrylic paint has additives in it to reduce foaming and froth, but sometimes you can end up with a frothy mix. You may encounter this mainly when mixing paint with mediums vigorously. 

Solution: Wipe it off with a cloth, clean your brush and start again. Or ignore it and if the paint dries with any bubbles or splotches, let it be part of the painting.

Paint Isn't Glossy

If an acrylic painting has dried with a matte finish rather than a glossy one as you'd expected, check the brand of paint you're using. Some manufacturers now produce acrylic that dries matte.

Solution: Mix in gloss medium when the painting's finished, apply a few coats of gloss varnish.