The "in" bag is a lighter, brighter model ... and it must have wheels.
Mintel, the market research company, publishes a survey this week which shows that the days when all that mattered was to own a case that was durable and secure are over. An attractive design, colour and integral wheels are now more important to tourists.
The change began 10 years ago with young travellers. According to Antler, one of the biggest suitcase firms, the Eighties bumbag was the start of what they term "the rucksack revolution wannabe feeling" and the backpack helped change people's attitudes to luggage.
Brian Wreford, Antler's marketing director, said: "The minute people put bags on their backs they become mountaineers or outdoor adventurers."
Since then, business has boomed, with a sales rise of 15 per cent in the past six months, according to the British Luggage and Leather Goods Association. A recent survey by National Opinion Polls shows that people are no longer content with one bag for all the trips they take. More than a quarter of travellers consider buying luggage each time they go abroad.
Today, people buy a bag for sports equipment, a bag for short trips, fashion bags, and upright trolley cases for longer visits abroad. Green, once considered unlucky, is the favourite colour.
The most popular recent innovation is the bag with a fully retractable long handle and built-in wheels. This makes an easy-to-use travel trolley.
The upright hand-baggage trolley case has become popular because airline passengers have grown fed up with long waits at the airport carousels. Instead, passengers want to confine their luggage to the cabin.
British Airways has noticed that people want to take more baggage into the cabin. It is now considering making luggage under its own label to fit perfectly in the overhead bins.