Now, what I’m referring to here is not proper surface primer application, which by the way should be oil based. Instead, I wanted to point out advantages about painting on a un stretched canvas.
Over the last several years, I’ve painted almost exclusively on an un stretched canvas or as an alternate, on a Mylar surface. This gives me much more flexibility with my work if I want to add more surface area or deduct some.
When you paint on a pre stretched/prepared canvas, you are limited within those dimensions to create a pleasing composition. A lot of times, you will find that a finished painting would be much more pleasing if it was larger or smaller. Maybe the subject matter is too constrictive within the frame or the empty space needs to be reduced. And because your surface is stretched, you cannot do anything about it but scrap the painting and start anew.
There are 2 ways to solve this inevitable problem that you will face:
1. When you stretch your canvas (If you have to paint on a stretched canvas), leave ample fabric on all 4 sides that will allow for retrenching should you need it. This is in case you want to add more painting surface then originally thought.
2. Get a sturdy peace of hardboard and masking tape your canvas on it while you paint. Then upon completion, decide the final composition and crop and stretch accordingly.
Here is a visual example:
-There were aspects of this painting that I liked, and a large section that lacked visual appeal. This was a painting that was pre stretched, with about 6 inches of canvas left over on each of the 4 sides. In case I wanted to extend the painting, I had the option.
-After some deliberation I decided to crop the work, choosing to have the dark mobile mass as my center of interest.
-I cut the canvas to size, and stretched the painting on a smaller frame.
The finished transformation, may not be exactly true to your vision, but isn’t art ever evolving and that’s what drives us to paint.