commonly used CAD/CAM system is that supplied oy Shoemaster (www.shoemaster.co.uk). This allows skilled operators to scan the feet and match each foot with the closest existing last contained within the CAD/CAM software library and to modify the last appropriately. More commonly, CAD/CAM technicians will not use the direct foot scanning facility, but will extract data from drafts or from impressions of feet and then use the same system to select and modify existing lasts, and then design a new last based on the modifications. Once the computer-assisted design modification (the CAD element) is complete, a computer-assisted milling machine (the CAM element) will produce the last. The last will be made either of a plastic material or, in rare, special cases, may be made of wood, either of redwood or of horn¬beam; woods which are virtually knotless. As knots in wood are of a different density to the remainder of the wood, it is not possible to make smooth, durable lasts from woods which contain natural knots.

Pattern design
The next stage in the process is to design the patterns for the upper of the shoe or boot. The number of pattern pieces required for the upper will depend on the design. The basic shoe upper will contain at least three pattern pieces. A traditional lace-up shoe will usually need pattern pieces for the medial and lateral quarters and for the vamp. However, if the design is more intricate, a larger number of pieces may be required for the vamp or for each quarter. It should

Clicking and pattern cutting
The actual cutting of upper pattern pieces is known as 'clicking'. In the volume footwear industry, metal cutters will be made for each pattern piece in each size and width fitting. These cutters look almost like pastry cutters but have sharp cutting edges. The process is known as 'clicking' because the cutter is pressed into the upper material using a compressed air, hand-operated press known as a 'clicker'. Where the shoe uppers are made of leather, the cutters are placed with precision on an appropriate part of an animal hide suitable for use in the specific upper section to be cut. This is an extremely skilled task, as to use a hide economically with little waste takes much expertise. The craftsman cutter will use his skill to cut certain parts of the shoe from parts of the skin with specific features. Leather is a natural material and will contain many scars where the animal has injured itself during its lifetime or where it has suffered from skin lesions. These marks in the hide need to be avoided. Similarly, parts of the hide, for example in the belly area, will be thinner than those on other parts, for example the back of the animal. The cutter needs to know which part of the skin is best suited to particular parts of the shoe. Leather is an expensive material and skilled cutters can cut the hide with minimal wastage.
The art of pattern cutting is highly skilled, especially where leather is the chosen upper material. Even when CAD/CAM is used, the cutter may guide




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Note added at 3 hrs (2016-08-17 01:26:43 GMT)
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Therapeutic Footwear: A Comprehensive Guide
https://books.google.hu/books?id=vv42cV1onzcC&pg=PA51&lpg=PA...

"The term 'clicking' derived from the sound of the cutting blade exiting the leather skin and clipping the brass bound side of the pattern."