These range from the timeless (Toblerones and KitKats looked much the same in the 1930s as they look today) through the deliberately timely (all that coronation paraphernalia from 1953) to the accidentally ephemeral (Imperial Leather, Dove and Lifebuoy soaps live on - but what of Lightning, Bodyguard, Lily White, New-Pin and Puritan?).
As a celebration of the general fickleness and occasional fidelity of consumer culture, the museum is at once a reassuring and worrying place for investors. The case for owning shares in consumer goods companies such as Unilever (ULVR) and PZ Cussons (PZC) is that they can maintain interest in their branded products through a canny mixture of innovation, continuity and promotion. This should allow them to churn out dividends that roughly track consumers' disposable income. Their shares then become not just an inflation hedge, but also a play on global growth.
The appeal of this investment thesis has waned with the growth profile and currencies of emerging markets over the past year. But perhaps a bigger long-term threat lies closer to home: the rise of supermarkets' own brands.
Two decades ago, just over a quarter of consumer goods sold in Britain were private label, according to research outfit Kantar Worldpanel. As big supermarkets grabbed market share and developed more own-brand ranges - including upmarket ones ('Tesco Finest') - they pushed that share up to 46 per cent. This figure has remained steady since about 2005, but could be given a renewed boost by the latest big disruption to hit the grocery business: the breakneck expansion of discounters. At Kantar's latest count, Aldi and Lidl - which hold a much higher share of private-label products - were showing annual UK sales growth of 36 and 21 per cent, respectively.
This is not just a British trend. "The rise of the discounter is a challenge across the modern world," says Clive Black of Shore Capital. Following consistent gains, private label accounts for about 30 per cent of the consumer pie in Western Europe. Growth has been more rapid still in Eastern Europe, albeit from a lower base. Private label has even been taking market share in the USA, historical bastion of the brand.
Some products are more resistant to white labelling than others. Broadly, the more manufactured the product, the better it lends itself to differentiation and hence branding. So there are few brands in fresh and chilled produce, but plenty in healthcare and toiletries. In defiance of the wider trend, healthcare brands are actually gaining market share in Britain, according to Kantar Worldpanel.
This pattern also shows up in corporate results. In the first quarter, Unilever's underlying sales growth was 4.5 per cent in personal care (brands like Dove, Lux and Vaseline) and 7.4 per cent in home care (various detergents and cleaning products). Meanwhile, underlying growth in food was -1.7 per cent. That was partly explained by the timing of Easter, but food was also the worst performer in 2013, with growth of just 0.3 per cent.
It doesn't help that Unilever's product portfolio is dominated by unfashionable margarines. The company, which was forged by the 1929 merger of Dutch margarine maker Margarine Unie with British soap maker Lever Brothers, recently gave up a very long-standing fight against butter, which it has now added to its spread ranges. But the problems may be afflicting other products too. The company announced the sale of its Ragu and Bertolli pasta sauce brands this month.
Nestle's (Ch: NESN) food business is also its weakest link. Organic growth within the 'prepared dishes and cooking aids' category - mainly Maggi pot noodles - was 0.3 per cent last year, while nutrition and healthcare grew 7.6 per cent. We may associate Nestle with chocolate, but its "long-term strategic direction is to be the leader in nutrition, health and wellness".
Supermarkets' own-label ranges come at the end of the story told by the Museum of Brands. The discounters pose a big threat - and perhaps the museum will soon feature Aldi products. But I am still tempted to echo Lord Lee's thoughts in his latest FT Money column: supermarket shares look cheap. Wm Morrison's (MRW) stock is trading below book value, giving a forward dividend yield of 6.7 per cent. Sainsbury's (SBRY) is on 11 times forward earnings, compared to a 10-year average of nearly 17. Their groceries may no longer offer the best value - but perhaps their shares do.
