"Suede effect" and cold-pressed linseed oil

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"Suede effect" and cold-pressed linseed oil
In the 50s, a paper was delivered by a conservator surnamed Gluck offering a theory as to why modern tube colors exhibited that obnoxious "suede effect" (i.e. a tendency toward a kind of dichromism where the value of a passage would shift depending on the angle at which one viewed it). She(?) went on to state that this effect was never observed by older painters working with tube colors in the earlier part of the century and that some recent change in the method of manufacture of these paints must account for this change. Her research led her to believe that it was the fact that increasingly the oils used in tube colors where expressed with high heat and pressure. This finding seems to have prompted Winsor Newton to obtain and offer unrefined cold-pressed linseed (flax?) oil for those wishing to grind their own colors and avoid the suede effect. I tried this oil and found that it was too dark for the whites, but I am wondering if anyone has an idea of what, indeed, does cause the suede effect. My own
hunch is that the older colors were not ground with so much pressure and for such a long time and therefor had a higher oil content than some of the contemporary premium brands. I have noticed that some of the cheaper "economy" grades of paint such as Winton and Brera do not exhibit so much this effect and I attribute it to a higher oil content and more gentle and less prolonged grinding (more like hand grinding). Certain additives may also be implicated in the suede effect. Can anyone shed light on this vexing problem?
Re: "Suede effect" and cold-pressed linseed oil C. Maltais Posted at: 08/23/00 (3)
Re: "Suede effect" and cold-pressed linseed oil James Morton Posted at: 08/23/00 (2)
Re: "Suede effect" and cold-pressed linseed oil rob howard Posted at: 08/23/00 (1)
Re: "Suede effect" and cold-pressed linseed oil rofl Posted at: 09/07/00 (0)
Re: "Suede effect" and cold-pressed linseed oil James Morton Posted at: 08/23/00 (2)
Re: "Suede effect" and cold-pressed linseed oil rob howard Posted at: 08/23/00 (1)
Re: "Suede effect" and cold-pressed linseed oil James Morton