It's not necessary. The gap between canvas and frame is typically 1/8 to 1/4 inch, so not much light gets in. Personally, I prefer the edges not be painted.
My big thing ...is. Frames are not complicated. If you want a frame and it's not for canvas, it can still be used. Canvas can be mounted on thin material to fit ANY frame. Paper can be placed on canvas stretchers just like canvas to frame in a canvas frame or metal
Just ordered some samples. I’m trying to dress up a donated piece to support veterans through a non profit than you for making your samples readily available.
NO. Canvas does NOT need to breathe. It hasn't got lungs. This has been asserted by knowledgable conservators many times. The solvents in the medium will off-gass from the front.
El marco flotante enmarca muy bien la pintura. Hay reproducciones de formato grande de 50cmx121 cm, en papel canson 230 grms. donde podria obtener informacion para el enmarcado de esas obras,gracias.