acid and disperse dyes such assistants being a combination of dibenzyl ether with a compound of the formula str1 wherein x is selected from the group consisting of hydrogen methyl and ethyl application_number US 91226578 A description dibenzyl ether alone was found to be an effective dyeing assistant for acid dyeing of specialty nylons comprising 40 or greater of the condensation product of 4 4 39 diamino dicyclohexyl methane and decanodicarboxylic acid having the basic repeating unit str3 however it did not give optimum results with disperse dyes with this specialty nylon a representative alkylene carbonate did not give optimum results with either acid or disperse dyes however combinations of dibenzyl ether with certain alkylene carbonates gave assistants whose performance could not be predicted by a mere arithmetic averaging of the properties of the individual constituents since the combinations generally were effective for both acid and disperse dyeing of the aforedescribed specialty nylons it was further observed that when dyeing the aforedescribed specialty nylon dye compositions comprising the disperse dye eastman polyester navy blue 2r lsw eastmand chemical products inc c i disperse blue 79 with the combinations as assistants gave commercially acceptable dyeing results this contrasts with the outcome found when the individual members of the combinations were used with this dye all gave unacceptable results due to the dyed fiber being a blue gray hue rather than a navy blue or due to uneven dyeing or due to incomplete.