Increasingly, however, computers are used to determine the optimum arrangement of the pattern pieces. Using an electric knife or other cutting tool, other workers cut out the various pieces of material following the outline of the pattern. On especially delicate or valuable items, this may be done by hand. Workers must pay close attention to detail because a mistake in the cutting process can ruin many yards of material. In more automated firms, electronic copies of layouts are sent to computer-controlled cutting machines.
Workers then monitor the machine.
Once the material has been cut, it is ready to be sewn together into a shirt, knapsack, dress, or other product. Most sewing is done by sewing machine operators, who are classified by the type of machine and the type of product on which they work. Because each product requires a variety of sewing operations and all of these cannot be done on the same machine companies producing apparel have many types of specialized sewing machines. Sewing machine operators' skills vary by the type of machine on which they work. Sewing machine operators are also categorized by the specific product they produce.