AbstractA study of the weather resistance of porcelain enameled architectural panels was begun at the National Bureau of Standards in 1939. The study involved 864 one‐foot‐square panels and an equal number of 4‐ by 6‐in. laboratory specimens. A previous report (1942) gave the results after one year of exposure. The present paper describes the condition of the panels after seven years of weathering in Washington, D. C., St. Louis, Mo., Lakeland, Fla., and Atlantic City, N. J.The results of the seven‐year inspection showed good correlation between the acid resistance of enamels and their resistance to weathering. When initial coverage was complete and no mechanical damage had occurred, protection of the metal by the enamel for all specimens was unimpaired after seven years. Colored enamels faded only on panels having poor acid r