Train-spotter's guide to kitsch and tat: John Windsor dons his anorak and goes in search of the stuff you would not have in your house

IT IS not obligatory to have an implacable hatred of proletarian culture to be a tat hunter. Being a snob is sufficient.

What I really wanted when I scoured Brick Lane market last weekend was one of those abstract string-and-pins pictures. Or a framed steam locomotive made from watch parts. They seemed to be fresh out of them. Which was a bit worrying. Disbelieving the old saw that 'everything is collectable', I had thought I had the market in tat to myself.

Sensing competition, I have now embarked on a different game: trying to make the uncollectable collectable. It is all a matter of what marketing people call 'product definition'. Tat, you understand, is not rubbish. Nor is it kitsch. Tat is the sort of junk that ends up with owners unspoilt by either education or taste, persons able to tuck shirt into underpants without a qualm.

Let me explain. You know what junk is - cheap, secondhand goods. Take away from it rubbish (as dustmen do) and kitsch (as Jeff Koons does) and you are left with tat, secondhand fancy goods which inhabit a Shangri-La of their own.

In this twilight Tattyland, wood smoke is rising from thatched cottages with rose-entwined porches. In the freshly ploughed fields, leather strops of bright brasses jingle round the necks of sturdy Shire horses. In the lane, a new-fangled automobile, carrying the squire and his antique firearms to a shoot, honks its polished horn.

There is a place for everything in Tattyland. Letters have their own racks. So do periodicals. There are even matchbox-holders and 'spec rests'.

Inside the cottages, everything is tiny. There are tiny gongs to bang for tiny teas. There are tiny warming pans and tiny ornaments made from tiny shells. Tiny shields and tiny swords on the wall are a wondrous sight for tiny tots who shed glistening tears as they listen to stories of the Good Old Days.

More tears of joy are shed by the vulgar old codgers at the inn, who quaff from tankards marked 'Went to P, leave this drink alone'. They never stop smiling because they are allowed to drink and smoke 'like Helen B Merry'.

All around them are comforts which are cheap, old-fashioned and good. Their cheap, plastic tankards (20p) are shaped like good, old-fashioned barrels and have chunky handles made from good, old-fashioned wood.

In Tattyland, if a cloud crosses the sky it is necessary only to look at the image of a good, old-fashioned cottage or barrel or laden galleon or horse brass or steam engine or heraldic shield to bring dimples back to the cheeks. There is nothing like a repro Staffordshire spaniel (50p, good originals fetch pounds 700- pounds 1,000) to spread a glow of good living. Or an ice bucket with a horse's head, tiny stirrups and what look like thongs of genuine leather ( pounds 1.50), to rekindle the noblest aspirations.

Such is the conceptual art of simple-minded Tattyland. Do not mock. If you do, your simple- mindedness will disappear and your tat will transmogrify as kitsch. Then you will be sorry.

Jeff Koons, the wicked American wizard, turns tat into kitsch by making it out of expensive materials, such as his stainless steel cast of a rubber-balloon rabbit (1986).

To protect your tat from the wizard, you must make sure it is made from cheap materials such as plastic or plaster. The big round wall plaque with cottage in relief ( pounds 2) will never become kitsch because it is made of plaster. Nor will the pair of cheap plastic-and- velour praying children wall decorations ( pounds 1). But the wood and alloy pistol ( pounds 5) had better beware of the wizard because someone put too much craftsmanship into the metalwork. Pistols in cast brass or plaster are safer.

Kitsch is as self-conscious as tat is simple-minded. Kitsch is camp. Tat is naff. Unlike kitsch, tat does not invite you to think twice. It is what it is: imitative in a forelock- tugging way. Kitsch is sentimental. Tat is sentimental and nostalgic. Each piece of tat is a happy reminder of things past. Which is why all souvenirs not made of solid gold are tat.

It was the souvenir industry which liberated fancy goods from the dictates of the design-conscious. Why remain in awe of nature's handiwork in cockle and mussel shells when you can stick them together to make a funny bunny to sell to seaside holidaymakers? The same holidaying Tattylanders appreciate gnomes made of fir cones, pictures of flowers made from sliced shells - and a mustard pot disguised as a tiny teapot (marked 'Dartmeet').

Beware invaders in Tattyland. The half-dozen Sixties miniature coloured-glass tumblers in the wire boat are tat, but the boat itself with its wire-and-blob 'coolie' ferryman was inspired by the late-Forties 'New Look'. The piece is collectable and probably worth 10 times the pounds 2 I paid.

The ceramic teapot cat with paw for a spout (on telephone stand, pounds 5) is highly suspect. Is it innocent, badly designed tat or a provocative piece of kitsch? Remember that while kitsch poses, tat simply pretends. What is this pussy cat up to?

The Sixties glass fish is a changeling. It started off expensive and kitsch, is tat today but could be kitsch again tomorrow. Traders are forever trying to turn tat into kitsch. In Brick Lane I was offered for pounds 5 a glazed postcard of the Mona Lisa with passe- partout frame ('It's a work of art,' the trader said) and for pounds 20 a pink plastic table lamp in the form of a Deco- style lady described first as soapstone and then, when I raised an eyebrow, as Bakelite. Both genuine tat, worth 10p and pounds 1.

But I got a shock when I stumbled across a genuine tat shop, 'Wally's North London No 1 Antiquated Shop' at 217 Stoke Newington High Street, London N16. There was my 20p 'P' tankard priced at pounds 5 and my pounds 4 glass fish at pounds 10. The proprietors' regrets that they could not supply me with a string picture were accompanied by no knowing smirks, no nods or winks. I became aware of the delicacy of the situation. A careless jest or curl of the lip from me and the whole stock of cheaply bought tat might disappear in a puff of smoke, only to reappear as kitsch. I zipped up my anorak and left.

Wally's (081-985 6068).

The Jeff Koons Handbook (Thames and Hudson, pounds 9.95).

(Photograph omitted)