The accelerated light aging of fourteen dyestuffs dissolved in epoxy (Ablebond 342-1), polyester (Metset SW) and acrylic (Plastogen G) resins has been studied. The dyes show good light stability in acrylic medium but more dramatic photofading in polyester and epoxy resins. The color changes, measured instrumentally and plotted in CIELAB color space, indicate that fading is accompanied by a change in hue in certain cases. The undyed acrylic resin yellows more than the epoxy and polyester resins, but certain dyes stabilize the acrylic substrate against yellowing. On the other hand, for some dyed epoxy resin casts, the degradation and yellowing of the resin is accelerated compared to the undyed samples. Considerable recovery of color on dark storage after light aging is a significant feature of the behavior of four of the dyes. These observations demonstrate the inadvisability of using dyed polymers for con servation without first testing the lightfastness of the dye/resin combination.