The size of pre-forms is adjusted by using interchangeable toe pieces

With the exception of Nylons, they are packed one or two dozens at a time into cotton sacks and placed into rotary scouring vats and, in unlimited quantities of soap and water, all dirt and grease and dust being removed.

Pre-boarding.  After scouring, silk, cotton and rayon stockings are ready for the dye house. Nylons stockings, however are subjected, before being scoured, to an operation which prevents the stitches becoming distorted during the dyeing process. This is known as pre-boarding. (The term pre-boarding is used to distinguish the operation from boarding, to which all stockings are subjected after dyeing.) Pre-boarding consist of placing the Nylon hose on steel leg-shaped forms, placing the forms in a sealed container, raising the temperature to approximately 240°F., and at the same time increasing the pressure. The total time taken for this operation is approximately two minutes.

The pre-boarding operation does, unlike normal washing of the stockings, shrink the fibres slightly. The leg shapes on to which the stocking is placed are so designed that they will accommodate the whole normal range of stocking sizes and thus flexibility of size is achieved by making the toe piece of the metal shape separate from the heel and leg section. A complete range of foot sizes may be obtained by placing the suitably sized toe piece on to the foot section of the shape.

To allow for shrinkage, nylon stockings are made slightly oversize and there are also slight differences in the positioning and number of fashionings or narrowings in the stocking. The machine used for pre-boarding is semi-automatic, and the stockings are subjected to the treatment in dozens—that is twenty-four at a time as the term dozen in the hosiery industry always refers to a dozen pairs. The metal forms over which the stockings have been drawn are pushed into a steam-heated oven and left for the approximate two-minute period, after which the machine automatically withdraws them and the oven is ready to accommodate the next dozen. The stocking that measures thirty-two-and-a-half inches in the leg before pre-boarding, will be about thirty-one inches long after the process is completed. After pre-boarding nylons are scoured in the same manner as other stockings and they they, too, are ready for dyeing.