Three photographic printing papers were used to prepare stepped grey scale strips. Processing variables involved in the preparation of the strips included: 1) the use of a sulfite-type washing aid which was used in conjunction with shortened washing times; and b) post-processing treatment of the strips with Kodak Rapid Selenium Toner solution in several different dilutions. Untoned reference samples were also produced. The strips were subjected to various hydrogen peroxide and hydrogen sulfide vapor environments. The results, as monitored by densitometric and spectrophotometric methods, indicate the selenium toned samples to be protected against oxidative degradation in peroxide environments. This protective effect is evidenced with all toner dilutions, including those which are sufficiently dilute to leave the image color unchanged. The use of washing aids during processing did not affect the stability of the samples under the test conditions. -- AATA