Fundamentals of Wearable Computers and Augmented Reality, 2nd Edition

624 Fundamentals of Wearable Computers and Augmented Reality

much more secure than a chain stitch, and unravels slowly by pulling the two pieces

of fabric apart. The lockstitch is perhaps the most common sewing operation, used

to make body seams as well as nishing seams, trim attachments, and many other

operations. Its biggest drawback is that it does not stretch (nor does a chain stitch)

and therefore cannot be used to form extensible seams (such as in stretchy materials).

As seen in Figure 23.4, the interlock between the bobbin and needle thread is

typically located in the middle of the fabric piece or seam. This reduces wear and

tear on the ...