Why do artist's prefer primed surfaces over unprimed surfaces?
Some artists, especially those of the last century, began to experiment with thin washes of colors onto the raw canvas and liked the staining effects. However, the oil paints were a problem because of the acidic nature and this is a problem for the museums and conservators who are trying to preserve them. In the 50's Bocour Artist Colors (no longer in business) made the first synthetic artist paints called MAGNA. These paints allowed the painter to apply washes of a Mineral Spirit Acrylic binder (MSA) to the canvas and not worry about acidic qualities because these paints didn't have that problem.

The drawback was these are solvent-based paints and large washes meant lots of solvent in the air of the studio. In the 60's, water-based acrylics were being produced and the “color field” artists had a much safer environment to work in. The look of stained canvas is unique, but there is still a concern of longevity because the washy, thin films are not going to protect the canvas from the environment. Moisture, grime and pollutants can still attack the fabric much the same as any piece of fabric.

The solution, without compromising the look of the stained canvas is to seal the surface after the artwork is complete with an isolation coat of acrylic medium, and then varnish to return the canvas to looking like it is uncoated. Artists also can prime and apply GOLDEN Absorbent Ground, which mimics paper or raw canvas' absorbency.

Thicker paints, like our Heavy Body Acrylics (tube paints) can be applied to unprimed canvas, but it's essential to make sure they are being forced into the weave of the canvas to assure a good bond. Another solution is to use GOLDEN Matte Medium or Fluid Matte Medium as a "clear" gesso, before painting. This will allow one to leave areas unpainted, but still protected, even if they are not varnished.

Finally, most artists just simply like working on a bright white background as it tends to make the colors more vivid. We also have Black Gesso and you can mix them to make a neutral gray gesso, or you can try using GOLDEN High Load Acrylics, which are highly loaded paints in a gesso-like consistency. These would allow the artist to prime and paint at the same time.