It's always good to have greater depth of knowledge, and that is probably the chief benefit of mulling one's own oil paints. I wouldn't discard them just because they are not likely to outperform (in terms of enduring centuries with fewer defects developing) tube paints made on roller mills, as the unique handling properties ("long," relative to tube paints) of hand-mulled paints are sometimes preferable to the "short" handling of tube paints, for certain applications and styles of painting. The extra yellowing that results from a higher percentage of linseed oil will eventually bleach out in normal indoor light, and in any case does not significantly affect the color except in whites and blues. The other difference will be one of flexibility, the advantage going to tube paints on that score, most likely, due to the stabilizers added by the manufacturers, which tend to act as plasticizers in old oil paint films. This is not a cause for concern at all on rigid supports, and on stretched canvas it is not usually a major problem if the paint layer is not too thick. It's important to realize that things work in combinations, and the combinations are the context in which we must consider the performance of each component.
The Old Masters very likely worked with both long and short paints, using each for the purpose for which it was best suited. Long paints flow in the direction of the brush stroke, which makes them ideal for linear strokes that hold their own shape, whereas short paint tends to merge with wet paint on all sides of the stroke, more readily accommodating softer transitions from one tone to another, blending of edges, etc. Long paint is best for use with soft-hair brushes on smoother surfaces. Short paint is better in conjunction with hog- bristle brushes on more textured surfaces. The characteristics of the binding oil determine whether the resulting paint will be more long or more short. Walnut and poppy oil make short paint. Linseed oil makes relatively longer paint, varying according to how it was processed. My water-washed, sun-bleached linseed oil makes very long paint. Raw linseed oil would be less long. In tube paints ground in linseed oil, it is the stabilizers added in manufacture that give it the short characteristic. Short paint suffers less oil separation while sitting in the tube for months waiting to be sold.
Nothing is as simple as it seems.
Virgil Elliott
