There are many ways to skin a cat. There are also many ways to repair a jean. Here we discuss a few of the more common methods.
Darning
This is a common method of mending. Darning is done with a special machine that allows the operator to move the material freely.
Back-patching
This is were you apply the patch on the inside of the jean. It can offer a more aesthetically pleasing repair. It can also be used for helping to reinforce large holes that require darning.
Patching
Pretty basic here. A top patch is applied over a hole/tear and secured on with a stitch.
Sashiko
Means "little stabs" in Japanese. This is a delightful method of hand darning patterns over repairs. Time consuming, but beautiful.
Zig-zaging
In the absence of a darning machine, some repairists will use a zigzag stitch to help secure repairs. Effective, but doesn't offer the ability to mend certain harder to reach areas.
Thread-matching
A process of using multiple colors of thread for a repair to help match the tone (warp & weft weave) of worn denim.
Bar-tacking
A small tight series of stitches that is use to secure denim together. Often seen around the fly and on belt loops. Requires a specific machine for a proper bar-tack.
Reinforcing
When an area becomes threadbare, you can reinforce the area before it tears. This can be done via darning or patching depending on the size, location and severity of the thinned out area.
A thought or two on home repair:
Those denim iron on patches
Pretty cool to use. Will do in a pinch, but don't tend to last long. Can be used in conjunction with stitching
Hand sewing
Can be a decent option with the right amount of patience, correct thread and know-how. Most hand repairs don't work well. If you know what you're doing, it is a decent option.
Duct tape
No. Just don't. The adhesive with stay on your jeans forever.