Some photos from the March 29th Canvas stretching demo
Above: Preparing the surface of the linen with a coat of oil primer after first sizing the surface twice with the utrecht acrylic sizing to protect the fibers from the oil. I prefer to knife prime and buff out any marks that the knife leaves behind with a brush or piece of scrap fabric. This process with repeated sanding produces a very smooth service.
Above: This is for everyone that comes in looking for a way to paint directly onto the Linen for its wonderful color… You can size the linen and paint directly into it… BUT… proper adhesion of the paint film cannot be guaranteed. I prefer to prep the surafce as shown above; creating an imprimatura that is hand rubbed into the primed surface with a rag. The imprimatura should be just paint and turps/mineral spirits- any added oil will make it too “fat” for good adhesion. In this case I used a mixture of raw umber and mars black to produce a very linen-like tone. You can even begin to wipe your lights back out of the wet imprimatura, beginning the process of establishing the value structure of the painting. (the imprimatura is over two coats of utrecht acrylic sizing, and 3 coats of oil primer sanded in between each layer)
Above: Cotton canvas stretches in just the same manner- while not nearly as strong as linen it is a more economical choice