This unique personal collection of over 12,000 everyday items by consumer historian Robert Opie celebrates the mundane through the decades – the packaging and products that have formed a subtly integral part in our lives over the past 120 years. Crowded into cabinets, these relics serve as an unusual reflection of social and political changes, as well as some pretty canny advertising, from twentieth century Britain to the present day.

Entering the museum's 'time tunnel', walled with cabinets full of bottles, toys, soap-powder boxes and crisp packets from throughout the decades, the effect is gradually overwhelming. As you step through the years of memorabilia and relics amassed by Opie, it is staggering to think that this collection was not brought together by a large national museum, but is in fact a very personal obsession, amassed over the years by what must be one of the ultimate hoarders of all time. It seems clear that the sheer amount of stuff in this museum requires a special kind of passion: an artistic eye for identifying and appreciating what the great majority of people fail to observe or recognise – a recognition of the everyday.

This exhibition is able to speak for itself. The 'time tunnel' is packed fully all the way down from the 1890s to the present day and there is perhaps more on display than you can possibly take in and fully appreciate in one visit. More austere and monochrome products from the start of the century give way to bright colours, Art Deco and plastic, culminating in the 1970s and the 1980s technicolour cartoon characters and garish children's junk food. Fascinating in their reflection of historical changes in society and design, the canned peaches of the Victorian era are replaced by the modest Cadbury's chocolate bar, and still later by the bright sweets and dinosaur shaped chicken pieces from the 1990s.

Arguably, avid personal collections make for the best museum material, and you will inevitably become absorbed in some subtle niche, the most peculiar or rare artefact – the different variables from an often under-appreciated area of interest that has been the focus of a life's passion. And in this museum it is not surprising to find yourself gazing at the subtle changes in the design of a Head&Shoulders bottle through the years.

The recent addition to the display of topical Jubilee and royal wedding memorabilia makes for an intriguing thread that runs through the whole display. As the collection points out, starting with the marriage of Queen Victoria and Prince Albert, chocolate boxes, tea towels and china have accompanied every major royal event throughout the past century, and it is interesting that these souvenirs are included here. The royal family is a brand, and these products have allowed the masses some kind of personal momento, an involvement in monarchial rule, and some way of accessing the relationships and politics that are mostly only reposted on and not seen. This has perhaps resulted in some of the weirder items, such as a commemorative rubix cube for princess Diana and Prince Charles' wedding, a Golden Elizabeth II tea pot, and something called '16 miniature photographs of the royal family in a nut shell' – literally, in a painted nut shell.

The great pleasure of this collection is that these are items that have belonged to the general public. Often the products on display have been used through generations, for cooking dinner, washing bodies or having a fag. And it is interesting to discover the true power of classic brands, and the subliminal trust we have in these labels as our daily companions, to the extent that their preserved wrappers can trigger such a strong sense of nostalgia. This is a retrospective on ourselves, as well as a historical collection of advertising and graphic design, and almost all British visitors will have some emotional response. Drawing together these modest relics, an impressive picture emerges from the regular waste and junk that we normally throw away.

Museum of Brands, Packaging and AdvertisingPhoebe Crompton reviews the Museum of Brands, Packaging and Advertising.5