Post #1625024

@mwichary I think the most important contributor is probably light (ie photolysis) — red tends to be particularly sensitive to this so probably not a coincidence that three of your examples are red paint — but other contributors to weathering might include water, air (ie ozone), expansion/contraction with temperature (which is likely different for the paint and the substrate) etc. [This is a generally informed expert opinion, but I’m not a conservator or anything.]