What does "Jimping" mean?

Question

Jimping is a term used when describing knives, but I am unsure of what it really means.

See for example this description of a keychain-sized tool where jimping is mentioned, and even lauded for "working well". According to Wikipedia, Jimping is supposed to be a sort of decoration (on the dull side) of a one-bladed dagger (specifically, a Dirk).

Unfortunately, looking for a more precise explanation results, most of the time I am being asked if I just mistyped "jumping". :(

So what does it mean exactly? And what is the function?

Answer 1

Googling provided me with the following information.

From ebladestore:

Lashing Grommets/Jimping - These terms refer to notches that are designed into the back lower part of the blade for better thumb control.

From knifehog:

Jimping: Notches down the spine of a blade created to provide grip on a knife beyond the bolster.

A post by Chris Meyer on bladeforums provides a definition along with some pictures:

Jimps (or jimping) is what the groves on tang are called. They look good and help give you a better grip.

These are factory jimps on a new Dovo razor.

Answer 2

Because the question has the tag, here's the etymology.

Knife Anatomy, Parts, Names, Components, Definitions, and Terms says:

jimping

The old word, jimp that came from North England and Scotland, means neat, handsome, and slender in form. The knife industry designated regular, machined cuts or cross-hatched patterns on the back of the spine of the knife to improve traction of the fingertips jimping. They still call those regular spaced machine-made cuts jimping, but the in the custom and handmade knife world it has evolved into artistic filework. Jimping may be machine-cut by automated slitters, mills, or blades, but filework must be hand-cut. In my world, calling filework jimping is an insult.

The OED has the noun jimp as an obsolete Scottish meaning, from 1513:

1. A minute or subtle point; a trifling distinction; a quirk, subtlety; a tittle.

And from 1572:

2. A trick, prank.

They say it may be related to the Scottish and northern dialect adjective jimp, variously meaning slender, slim, delicate, graceful, neat or scanty; barely full; bare (measure).

Known in Scots since c1500; origin obscure. It has been compared with gim adj., ‘smart, spruce’, of the same age, and with jump adj., exact, precise, which appears later; but in neither case is the sense congruous.

It's also used as jimp-waisted, such as this from 1826:

That bonnie dark-haired..jimp-waisted lassie.