Selvage

selvage [SEL-vij]
n. the edge of woven fabric finished so as to prevent raveling, often in a narrow tape effect, different from the body of the fabric

[From late Middle English self + edge]

Selvage the noun can also be used in verb form. To selvage is "to finish a fabric so as to prevent raveling." Raveling itself is an odd word. To ravel ("to become disjoined thread by thread or fiber by fiber; to fray") means largely the same thing as to unravel ("to separate or disentangle the threads of a fabric"). The only difference is that unravel is used metaphorically as well ("to separate and clarify the elements of something mysterious or baffling").

I came across selvage in Tom Wolfe's A Man in Full and mistakenly thought it was a typo for salvage ("to save damaged material for further use"). Coincidentally, as Wolfe employs it, the uses are not far apart:

This in turn made him think of how second-rate his clothes were. This old gray pinstripe suit that had come back just a bit... shiny... from its last trip to the cleaners... the buttonhole in the front that was frayed and needed selvaging...

I'm sure selvaging is widely known by people who work with fabrics. Here it appears in a column called Simply Quilting:

The first thing I want you to do is find the selvage edges. These are the outside edges that run the length of the fabric and are usually one half to three quarter inches wide. Cut off the selvage.