This section is from the book "The Manufacture Of Boots And Shoes: Being A Modern Treatise Of All The Processes Of Making And Manufacturing Footgear", by F. Y. Golding. Also available from Amazon: The Manufacture Of Boots And Shoes.
Drafting, or draughting, is rendered necessary in the making of boots and shoes, owing to the material employed in their construction, and the cut of the upper. Leather is a flat substance, possessing stretch in varying directions, and has to be "blocked" or "lasted" to the different curvatures of lasts, during the manufacture, thus removing - according to the efficiency with which it is done - the superfluous expanding properties that would during wear - if not removed - cause a constant change in shape and measurement, making the goods unsightly and uncomfortable. To counteract this "giving" property of leather, the upper is drafted during making, this operation imparting a tension, strain, or draft in the upper from counter to toe, that insures the tendency of the upper to close together when removed from the last. When the weight of the body is transferred to the foot, and thus the strain is thrown upon the upper, the tension or draft prevents its undue yielding and consequent loose fit. This tendency of the opposite sides of the upper to approach each other is usually tested by taking the well-made boot, say, in the left hand by the sole, and then with the right alternately, gently pulling and releasing the leg portion of the boot. The set or sit of the boot depends upon this draft or tension.
The operation of drafting by the maker may in some instances be assisted by making a modification in the pattern; but such alteration to be effective must be based upon the same principles that are adopted by the laster. Much is done to a pattern with the idea of "drafting" that does not in the least assist in the process; so that it will be well at this stage to examine the fundamental principle. The longitudinal strain, produced by dropping the upper from the seat upon an inverted last, and by pulling it well over the toe by a series of correctly directed pulls, in fact, reduces the length of the bottom of the upper to that of a length from counter to toe. When the upper is pulled up at the back this shortened length has to be replenished by taking extra stretch from the upper, and this extra strain gives the tension, or draft. The sketch (Fig. 127) will make this clear. When the upper is pulled up at the seat it ensures the tension or draft along the line A. This is assisted by C and other "lines of pull" If the upper is very " dead " it is very difficult, if not impossible, to obtain efficient draft, and it will also be very tight in the waist. An upper with a springy toe will draft well, and the waist will be easy to last, but there will be surplus or "foul stuff" to dispose of somewhere in the fore part.
It is not necessary to draft a well-designed pattern, and to do so for some work would be a serious detriment to its manufacture. Drafting, when adopted, must not be done by taking an amount off the seat of the pattern, gradually diminishing to nothing at the waist, because this would only have the effect of making the heel-measure too small, causing an undue strain from instep to seat. Even when removed from the forme, before constructing the pattern, it is erroneous; by its lessening the measure from instep to corner of the heel, thus causing the instep of the upper to fit the last "too soon," the inclination thereby being affected. In a shoe, an amount must not be taken from the instep and left on at the waist with an idea of "draft," because this will reduce the long-heel measure, and the measurement from instep to joint making the upper difficult to last properly. Sometimes an amount is removed from the bottom of the pattern of a shoe and placed to the credit of the top of the back - keeping the transverse measure the same, it is true - but when the upper cut from this pattern is made, it will be too full in the waist, and the heel-measure will be too small.
The correct method of drafting a pattern, assuming that drafting is necessary, either boot or shoe, is shown in Fig. 128, where wxyz is the standard to be drafted. For light uppers the amount B is not to exceed 3/9 in., while for stouter work 2/9 in. would be sufficient. Shoes may have a little more, say J in., than boots. Having traced the outline of standard and decided B, place a finger on A and raise the pattern so that w coincides with B. Trace dotted outline YZ. Correct the length by making xB equal to xw. A pattern cut to fit the last properly, and curved as Fig. 114, with the correct leg position would not need to be "drafted;" while a pattern like Fig. 129 would be easier to last if drafted. When making the latter kind of upper, it should be pulled at D (Fig. 127) before raising the seat of the ripper, so that the correct inclination may be obtained. Before deciding to draft a pattern it should be ascertained if it correctly fits the last. If it be found to be "springy" at the toe it will not require so much draft, i.e. elevation from w to B (Fig. 128), as a closely fitting toe. The forme in Fig. 120 has the toe cut strictly to the last, and to obviate any spring the vamp-crease TV should be carried from V to the corner of the toe, or at least to N.