the distance separating the two upper die members and this momentary response enables the resultant configured fabric piece to attain a substantial temperature reduction perhaps on the order of 100 u00b0 f or more the upper die member shown in fig3 by the reference numeral 78 prevents the resultant configured fabric piece from fully opening up or moving any farther upward thereby enabling such piece to cool to the extent noted and thereby obviating the danger of localized overheating which could damage or destroy the fabric piece e g melting of synthetic fabric and also the need for a subsequent separate cooling stage accordingly the present upper die assembly successfully accommodates considerable automation of the creasing or folding process with considerably enhanced productivity in production as a consequence the upper die members 76 78 are required to be heat conductive but capable of being durable under the conditions of heat to which they are exposed e g about 250 u00b0 f about 350 u00b0 f preferably about 300 u00b0 f with respect to synthetic fabrics such as conventional polyesters and about 350 u00b0 f about 450 u00b0 f preferably about 400 u00b0 f for cotton and wool fabrics temperatures below the minimum temperatures of these rangers are generally insufficient and render the creasing or folding process inoperative whereas temperatures above the.