CAN/CGSB-4.2 No. 33-94 (R2013)

1.1 Finishing 1.1.1 This method contains procedures for finishing (smoothing) fabric after washing or dry cleaning. Three principal methods of pressing and a procedure for restoration after dimensional change are described. These procedures are usually used as follows: 1.1.1.1 Ironing - This method is applicable to washable fabrics. Such fabrics generally consist of cotton, linen, silk, acetate, rayon, most synthetic fibres, or mixtures of these. Washable fabrics consisting wholly or chiefly of wool may be ironed, but are preferably steam-pressed. 1.1.1.2 Steam Pressing - This method is applicable to washable fabrics consisting wholly or chiefly of wool, and to other fabrics such as silk, acetate, rayon, most synthetic fibres, or mixtures thereof, that are normally processed in dry cleaning establishments (includes wet and dry cleaning). 1.1.1.3 Steaming - This method is applicable to pile fabrics and certain other materials which should not be compressed, e.g. insulation battings. 1.1.1.4 Tension pressing - This method describes a procedure intended to recover non-permanent dimensional change which can be present in some specimens after normal cleansing and pressing procedures. It is applicable to woven fabrics. The procedure simulates the various amounts of tension practical to apply to a fabric during hand ironing, to remove any restorable types of shrinkage. This restorable type of shrinkage occurs when certain types of fabrics, notably crepes and some spun rayon fabrics, come in contact with moisture - e.g. in wetting, or wet processing. In such cases, pressing without tension (as in the standard shrinkage testing procedures) may give misleading results with respect to the shrinkage to be expected in normal hand ironing of wet-processed garments, or even in commercial finishing where tension may be applied during steaming or steam pressing in an attempt to restore a garment to its original dimensions. 1.2 Relaxation - The steaming procedure is also used to identify stress from the manufacturing process which may be present in a fabric. Steaming is used to relax a specimen and the resultant dimensional change is determined.