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.
In cutting up materials for economy, it is a great advantage to adopt some system of placing the patterns. The best system to use depends upon the class of work and the variety of qualities to be produced. The mode of manufacture will also have its influence in the selection of the best system to use for a certain pattern. The cut and height, as well as the shape, of the pattern will determine the best method to be adopted. All these conditions as well as the nature of the leather must be taken into consideration when adopting a system.
In cutting fabrics into linings, the width of lining and the height of pattern will decide whether the system illustrated in Figs. 162 or 163 is the most advantageous to adopt. If the arrangement of Fig. 162 carries the pattern across the width of the stuff so as to leave no waste at the side on the right hand, then it should be adopted. A waste may be avoided on some widths by resorting to system Fig. 163.
The arrow head in this illustration shows the direction of the greatest strength of the lining. The warp threads running the length of the material are the strongest, while those threads that go across, the weft or woof, are relatively not so strong in the ordinary lining. The quality of both threads should be considered when making a selection for a particular purpose. In many workshops vamp linings for shoes are cut so that the toe runs width-ways, the strongest threads being across the vamp. This cutting of the lining is also resorted to in bal and buttoned work by some, to avoid the wrinkly appearance of the lining in the made-up goods. It is used for striped linings when the stripe is required to run the height of the boot. In some cases it certainly does facilitate the clearing of the linings. This is illustrated in Fig. 164. It is also advocated by some to prevent the tearing of the lining when first pulled over the toe during the lasting.
With certain shaped patterns and suitable leather, it is often advisable to adopt and adhere to a uniform system of placing the patterns upon the material, to get the most economical results. Rather than get out of range, the cutter would proceed as though no flaws, etc., were present, utilizing the damaged portion for some smaller pattern, so that the greater waste which would result from the up-setting of the uniformity of the system may be avoided. After a system has been selected that allows the pattern in conjunction with its neighbours to occupy the least surface space, care should be taken to strictly keep to the system. Broad, large skins lend themselves to the adoption of systems, the larger the skin and the smaller the pattern in proportion, the easier to use the system. Small patterns and large skins are the conditions that most advantageously repay the adoption of a system of placing the patterns. A system may be used that will get the best results as far as the cutting area is concerned, which would not be advisable to adopt if other circumstances were present and were deemed important. The size and substance of the skin, and the levelness of the remaining skins in the parcel, would influence the determination of the best method to adopt in the case under consideration. For the production of large quantities of work, where the skins are fairly level in substance, texture, and stretchiness, a system that produces work all for one side could be used, whereas with skins that are very irregular and that are very difficult to match up, a system that produces the work to match would be to the greater advantage in the long run, so that for small quantities of work, irregular skins, grained leathers, and many sorts of coloured goods, a system of placing the patterns that lends easily to the matching as the work is proceeded with would be recommended. But for large quantities of a particular pattern with skins of fairly uniform characteristics, the system that calls for the least space may be adopted, even though the work produced is for one side in the first skin, demanding another skin of suitable quality, etc., to be cut up with the pattern reversed. Some portions of men's patterns are better adapted to the utilization of systems than the patterns of women's work. The latter are larger in proportion to the skin than the former. When systematic placing cannot be resorted to, then the edges of patterns having similar curves should be arranged to meet, and the straight-edges placed to corresponding ones in the next pattern. The shape of the same design of pattern, the height, the heel and instep measure, will make a considerable difference in the amount of material used. This may be understood by testing a couple of men's leg patterns upon a sheet of paper, marking the same number of patterns employing different systems, and afterwards carefully measuring and comparing the area occupied. Figs. 165, 166, and 167 illustrate three systems of placing a pattern. They are taken from a standard pattern cut for a person with a flat foot and low-angled heel-measure (refer to p. 42). The leg is also low in height.
In system Fig. 165, the back of the pattern is made to fall upon a straight line, AB, and, without reversing the pattern, the toe is made to touch the throat curve of the first row, at the same time also keeping the backs of the second row in a straight line. This, of course, produces the work all one way, needing a second skin to be selected of similar quality, and cut with the reversed pattern upon the same system. Fig. 166 shows the same kind of pattern placed so that the top front corner and the toe touches the straight line AB. The work is produced all one way by this method of placing. The other way illustrated is Fig. 167. Work cut upon this plan faces or matches without having to cut into a second skin. By carefully calculating the surface-area of a number of the marked-out pattern, it can be seen which will cut into the least material (see also p. 241).
If a pattern of a greater heel-angle and a different style of top, as well as being higher in the leg, be used for the self-same systems, it will be demonstrated without doubt that the shape, size, and height of a pattern will influence the selection of the system that will produce a given number of parts in a minimum of area. Fig. 168 shows the same system as illustrated in Fig. 165, adapted to a skin. The line AB is supposed to be the backbone or centre of the skin. It will be seen, without measurement, to cut into more material than the pattern used for Fig. 165. The work produced on this plan matches the quarters cut on the right-hand side of the line AB. The pattern used for the next illustration is reduced from a standard cut with a heel-angle line of 42°. The line AB (Fig. 169) is used to keep the front of the top of the leg and the toe in line. It should be carefully studied in conjunction with Fig. 166. Fig. 170 is the same shaped pattern as that shown in Figs. 168 and 169. The work is produced for both sides. The pattern in the illustration is reversed in the right-hand portion for variety.
The interlocking of goloshes will be readily understood by reference to Fig. 124, given on p. 148. Large, level skins are those that allow this method of cutting to be adopted with the best results. Very small skins that fall away at the sides are best cut upon the system illustrated by Fig. 125A, p. 149, where the chained outline YXmn indicates the pattern required.
Vamps may also be run in upon a system, and is shown by Fig. 171. Here the shape has been sacrificed to produce a perfectly interlocking vamp - a course not advisable. Fig. 123, on p. 147, also shows the same system, which is generally adapted in long-winged, low vamps. For short vamps that are cut without spring, and where a large surface of material presents itself, they may be made to "run in" on the plan given in Fig. 122 A on p. 145.
Elastic-side fronts and backs may also be worked to a system, and Fig. 172 illustrates a seam-fronted elastic-side pattern, and the mode of placing them to cut into the least possible area. If the front be capped and the material underneath be removed therefrom, a variation of the system will be necessary to get the smallest cutting area. Fig. 173 is the system for a straight-capped front. The system of running the backs is exhibited in Fig. 174.
Systems for placing shoe quarters are given in Figs. 175 and 176. Shoe linings, top-bands, inside and outside straps, counters, tongues, and many other sectional patterns may also be arranged to be cut upon a system, but the illustrations here given will make the principle quite plain.