As linseed oil ages, hydrolysis and oxidation produce acid groups on the polymer chain that may lead to ionomeric behavior. The effect of these changes is difficult to determine in old paints because of the lack of records of environmental and treatment histories that can alter the physical properties significantly. A series of paints were made that have chemical properties similar to those of aged paints and that mimic old paints. Their properties seem to show flexibility as well as coherency but low strength and a high susceptibility to solvents.