An examination of Rothko's murals for Houston's Rothko Chapel considers their deteriorating condition and departure from traditional technique. Stylistic types are reviewed. Visual irregularities, structural disruptions, and general deterioration are discussed with specific regard to the effects of climate, previous treatment, and materials. Simulations of the artist's technique were created to evaluate the materials and to examine their behavior for similar defects. Observations made from the simulations suggest the cause of the current state of the paintings originates in the artist's choice of materials.