Objets czar: David Usborne’s collection of myriad objects is quite the mystery

I've always been a collector – even as a kid I had a collection of rocks. It's a sort of pathology that re-emerges at different stages of your life," says David Usborne. He's not kidding: his north London flat is absolutely stuffed. It might look like a jumble, but there are selection criteria: Usborne's twitchily collecting fingers are ever-reaching for "the useful, the mysterious and the anonymous".

Having studied history at university, then architecture, Usborne became a design teacher: "I find it easier to make k my point with things than with words – and that was a perfect excuse to browse around Portobello Road, antique fairs and junkyards [for] what other people might call junk, but which I find useful teaching aids." Now 73 and retired, his collection has turned into a website and book called Objectivity, and an exhibition in Lisbon (where he has another flat, also full of magpie finds).

"As I walk through junk fairs I'm attracted by elegance and mystery – the sense of: what is that?" he says. Pieces may also recall a face or a person and, as he explains, in "seeing a pair of callipers as striding figures, you're participating in the act of creation". But – crucially – none of the objects is "art".

"Visiting Tate Modern and – it sounds terrible – I come out with a contempt for the pretensions of artists and I reckon I can do just as well in the skip outside," he explains. "A lot of Damien Hirst's work is a riff on things he found in scientific collections which had no pretensions of being art – he simply transposed them. I prefer to do my own imagining and dispense with the artist."

This outlook has meant that galleries and museums aren't always keen to exhibit his collections. "Design museums tend to be committed to the authorship principle – iconic works by great designers. Anonymity isn't much valued; it's like an empty skeleton, it doesn't give anything for curators to work with."

This preference for anonymity also extends to his other love: quilts. "They are made from leftovers, the textile equivalent of salami," Usborne suggests. "They are, in my view, beautiful. Their added attraction is that they were mostly made by anonymous women. They look terrific, occupy large spaces, and let you off the hook vis-à-vis the named artist."

His website has explorable galleries showcasing his collection, organised by "function" (objects used for hitting or cutting, say), "context" (in hospitals, studios), or "metaphor" (faces, animals). The range is enormous, and curious... Can you spy the glass cucumber straighteners or hat stretcher in these photographs? A face-like chemist's balance or a claw-like carding tool? Some objects' purpose is virtually impossible to guess – turns out the thing he's holding on the previous page is an anemometer (for measuring wind speed at sea – duh!).

Does he have a favourite? "It's always the last one you bought. It gives you pleasure for about a week – then it's the addiction thing, you need another fix..."

David Usborne's collection is at Mude, the Lisbon Museum of Design and Fashion, until 30 September. For more of Usborne's collection, see: object-ivity.com