It’s true that I’ve used the same medium for several years. That doesn’t stop me from trying new materials–far from it! My invariable practice provides a baseline to which I can compare the new materials as they come into my hands. I can quickly determine if a new varnish or whatnot makes it into my toolbox.
I sometimes supplement my normal medium with sun-thickened oil. Unlike stand oil, sun-thickened oil retains its body when thinned. Plus, it holds a mark better than the too-leveling stand oil. No stand oil in my kit.
I’ve written before about James Groves’ materials. Not only are his varnishes and oils superior, but he also provides a wealth of information about his researches and experiments on his web site. I wish all manufacturers were as forthcoming as Groves. He is also an excellent painter.
Initially, I wasn’t interested in Groves’ Heat-Polymerized oil. I don’t use stand oil, as I said. But his heat-polymerized oil is not stand oil. Stand oil is made by heating oil in a carbon dioxide filled atmosphere. Groves’ heat-polymerized oil is heated but not in carbon dioxide.
Groves’ heat-polymerized oil is in a category of its own. It doesn’t handle like sun-thickened oil, nor is it leveling and viscous like stand oil. It’s wetting and enhances blending.
Groves’ heat-polymerized oil is excellent. I need more testing (I will buy more) but it’s very promising.