MITRA Forum Question Details

That should be fine. As the surface of the current canvas is slick, I would probably use 220 sandpaper on the existing ground to ensure that there is enough mechanical tooth to hold the ground. I would also wipe the surface with OMS and allow that to dry to make sure that you remove any greasy material that may have come in contact with the surface. Acrylic dispersions are great adhesives so it may not be necessary, but I can see no reason to not give it a preliminary cleaning and light sanding.

Acrylic-based mediums and grounds with pumice and garnet texture additives generally will accept oil paint in thin to moderate applications. The weight of these products can make lighter or larger canvases sag, so in my opinion, using a rigid support as you suggest is a good idea. If you are able to find a factory-prepared product that satisfies your process, I think that would be better than experimental DIY solutions which can't easily be tested to the standards of the industry. It's easy to add too much solid filler to acrylics without realizing at first that film strength has been affected; factory-prepared mediums, by comparison, are formulated with the benefit of performance testing that gives assurance that the film will not be crumbly.

Matthew, I was responding to his use of the commercially made product. I do agree that it is east to add too much additional material and create an underbound layer. Additionally, due to acrylic dispersion medium’s rapid drying, it may be difficult to properly disperse the amendment into the medium at home.

​Brian, I'm afraid I was still writing while you were posting. Sorry to step on your reply!

It is best this way as we tend to cover the things that the other did not think of.