35 to 40 by weight and most preferably at least 50 to 60 by weight of cotton or natural callulose fibers the fabric may be a resinated material but preferably it is unresinated it may be knit woven non woven or otherwise constructed it may be flat creased pleated hemmed or shaped prior to contact with the formaldehyde containing atmosphere after processing the formed crease proof fabric will maintain the desired configuration substantially for the life of the article in addition the article will have an excellent wash appearance even after repeated washings the equipment necessary to carry out the process is very much simplified since moisture control is not used as the moderator for the reaction the aqueous acid catalyst may be applied by padding or spraying moisturization of the fabric if additional moisture is necessary may be carried out by passing the fabric through a fog of water before entering the reaction chamber the fabric containing the latent catalyst may then be placed in a reaction chamber to which gaseous formaldehyde is supplied from any convenient source e g a formaldehyde generator wherein formaldehyde vapor is produced by heating para formaldehyde the formaldhyde vapors are diluted with air or other gas to provide the desired concentration preferably the formaldehyde is generated outside the chamber containing the fabric to reduce the fire hazard the reaction chamber is preferably one which can be heated to a sufficiently high temperature to insure that the cross linking reaction takes place the atmosphere in the reaction chamber is preferably a mixture containing from 1 to 6 5 formaldehyde gas by volume diluted with air or an inert gas such as nitrogen higher concentrations of formaldehyde could be used but are not required by this process to contact the fabric with formaldehyde.