Strictly speaking, knives fall into the general collecting catchall definition of „edged weapons”, along with battle axes, swords, bayonets, daggers, and so on.

The most spectacular collectable knife is surely the Bowie knife, named after its populariser and prime exponent, Jim Bowie. Bowie knives had great broad blades – some well over a foot long – with a hooked and sharpened leading edge to the point to enable the fighter to lunge upwards into his opponent in a lethal movement; they could also be thrown to devastating effect.
Although Bowies today enjoy a cult status in the United States (along with horn-handled hunting knives, also with elaborately decorated blades) they were made by an English company, Rogers of Sheffield, and exported in vast quantities in the mid-19th century.

Knives however are far more often involved in the business of life enhancement rather than life removal. Though the term „penknife” is generally taken to mean a folding pocket knife, some boasted fixed blades. However, the penknife’s original function (from the 17th century) – to shape and sharpen quill pens – is not in dispute, and penknives remained an essential writer’s desk tool, until the introduction of steel nibs.

Over the next two centuries the penknife developed into an object of great ingenuity, art and charm. Look for mother of pearl, horn, bone, silver (datable from the hall mark), carved, enamelled or relief decorated handles, some with foreign views or place names, intended as holiday souvenirs: a silver blade usually indicates a knife for cutting fruit. Knives with a bevy of blades – far more than any modern Swiss Army knife – were the pieces de resistance of Sheffield cutlers, each firm vying to outshine their neighbouring rivals in Victorian times.

Today’s collector covets penknives made for specific, often manly, purposes and pursuits, such as pipe-smoking (look for the various riddling, poking and tamping tools), fishing and shooting. One French locking knife from the 1970s has miniature quillons with hook points, shaped to grip and lever off the metal cap of a shotgun cartridge.

Ladies’ penknives were made in smaller sizes, with elaborately decorated, tortoiseshell or mother of pearl handles, to match sewing cases or etuis, or to hang from a chatelaine. Some had specifically feminine accoutrements besides blades, such as a button-hook, scissors or nail file. Knives in ingenious shapes or inscribed with advertising slogans and illustrations are also highly collected. Millers Price Guide (1999/2000) features numerous examples, including a pair of brass French penknives, C.1910, engraved with a classic car design (L15-L30/$24-$32 each); an angler’s knife with six attachments, the side plates engraved with hook sizes, c1930, L225-L245 ($360-$400); and a „Hardy (famous maker of fishing reels) nickle-silver ‘Drop Knife No1’, with dropping blade and screwdriver/file 1930-34 between L650-L800 ($1000-$1300).