Golden Paints Tests How To Prepare an Oil Paint CanvasJune 20, 2013
Golden Paints has for some time now shown themselves to be a reliable resource for thorough well-tested information about paint materials for artists, particularly acrylic media, but also for oil paints as it applies to using an oil and acrylic combination. Not too long ago Golden acquired the artist’s oil paint company Williamsburg which expanded their information and test results in that area. Golden has also made available for some time now an online newsletter called “Just Paint” that records much of these test results for the curious and concerned artist that I highly recommend reading. Their current issue has an article on properly preparing a canvas surface for oil painting.
The graphic chart they display, Table 1, is particularly interesting to me. It shows their test results for various sizing combinations in the number of coating layers applied, followed by a single layer of linseed oil ground, which then records how or if the oil penetrates through to the canvas surface below, as well as the degree of stiffness caused by the sizing. The results echo my own experiences with these materials, which is comforting.
In reading this chart notice that anything below a single coat of their GAC 100 product does not provide an adequate barrier to oil penetration (“Very Slight Strikethrough”.) An ideal canvas surface is reached with at least two coats of rabbit skin glue and a single coat of oil ground creating a stiffness that most traditional oil painters prefer to the more flexible acrylic dispersion mediums. Even when using acrylic “gesso” you would need at least three coats for an ideal barrier.
They give a summary of ideal conditions on their second chart. It’s important to note that if one uses just water-thinned acrylic medium or “gesso” they recommend waiting at least 3 days after applying the last coat for it to dry completely; something many artists don’t bother to do. What I see as interesting here is the minimum of two weeks time they suggest waiting for the oil ground to cure before you begin painting on it. Typically I see that at a far longer period of three to six months, unless you’re using an alkyd based ground in which just a few days curing time would be sufficient. The various options and conditions one could work in as well as your own preferences make the results difficult to qualify (“Your mileage may vary.”)
All in all, this is a very helpful article and I commend Golden’s authors Sarah Sands and Amy McKinnon for putting it together for us.