Bongo
Well-known member
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My research to find the source of the mysterious "spooky pentimento" lead me to the most recent rigorous scientific investigation on Support Induced Discoloration (SID) by Golden Paints.
Most of us rely on our own experience and/or the experience of others, but too often come to the wrong conclusions - because our experience is of a limited data set, and not done under strict scientific methods. In other words, much that you may have heard about SIDS and how to prevent panel warping --- is incorrect.
SIDs can only occur IF you use an acrylic gesso or an acrylic first coat. SIDS will not leach past that initial acrylic coat once it is dry. SIDS does not occur with oil paint -- can only occur on the first layer of acrylic paint put on the panel.
GLOSS MEDIUM and GAC100 can block SIDs but they do NOT provide a moisture barrier on wood. So if you're using those or similar products to seal wood and prevent warping - you need to use something else.
here's the link to the article.
justpaint.org
Most of us rely on our own experience and/or the experience of others, but too often come to the wrong conclusions - because our experience is of a limited data set, and not done under strict scientific methods. In other words, much that you may have heard about SIDS and how to prevent panel warping --- is incorrect.
SIDs can only occur IF you use an acrylic gesso or an acrylic first coat. SIDS will not leach past that initial acrylic coat once it is dry. SIDS does not occur with oil paint -- can only occur on the first layer of acrylic paint put on the panel.
GLOSS MEDIUM and GAC100 can block SIDs but they do NOT provide a moisture barrier on wood. So if you're using those or similar products to seal wood and prevent warping - you need to use something else.
here's the link to the article.
Blocking Support Induced Discoloration | Just Paint
Support Induced Discoloration or SID describes a phenomenon that can occur when the acrylic appears to change in color upon drying. It usually takes on a yellow, orange or brown tint, due to impurities in the substrate being drawn up into the acrylic film. The discoloration occurs while the...
justpaint.org
