Whether you call it royal memorabilia or kitsch, there has always been a healthy appetite for a variety of goods bearing the likeness of the monarch of their age. From tea towels to tankards, Royals have shipped more goods from traders' shelves over the year than Walt Disney's entire stable of characters.

Collectors are more than happy to lay their hands on items with royal connections: items once owned by, presented or even created by royals past and present. There are of course far more Charles and Diana plates around than dining room chairs made by Vicount Linley. Although the public's taste for cheap and cheerful items marking royal occasions and anniversaries is not what it was, we are still talking about mass production of collectables on an impressive scale.

In 1981 the full-page colour ads in the Sunday Express colour supplement were speaking in luridly expressive terms of 'gilt-edged investments' and 'heirlooms of the future' when trying to sell hand-painted plates of the royal couple costing in excess of £100.

Although modern royal memorabilia is worth collecting, you should not expect it to fund your pension - while the items made for Queen Elizabeth's Golden Jubilee is a guaranteed antique of tomorrow, you would need to wait 30 or 40 years for any real increase in value. A good tip is that portraits will always sell, whether it is an actual framed picture or on a plate or mug.

Pay attention to the quality of the piece - some carry fine and pleasing portraits, while others feature well reproduced high quality photographs. Try to avoid the shoddily copied shot lifted from the pages of the tabloid press. If you like caricature look out for the hugely sought after Fluck & Law Spitting Image-style mugs of Prince Charles. The popularity of royal memorabilia often fluctuates according to how much media attention is given to particular subjects. Virtually anything linked with Diana or bearing her likeness became desirable after her death in 1997, although the market seems to have returned to normal now.

Antique dealers who specialize in this area seem to think that items marking anniversaries for Diana's sons, the princes William and Harry, will become very popular and certainly sell well in the future, while items depicting Diana and her children sell better than items of Diana on her own.

Top Tips

• Portraits are key- any memorabilia with a royal face on it is likely to be more popular
• Look for matching pieces, i.e. loving cups relating to William and Harry
• Portraits of Diana with her children are more collectable than those of Diana on her own
• Prince William pieces are more collectable than Princy Harry - look for 21st birthday pieces
• Portraits of royal children are more desirable than those of older royals
• Buy for future generations - they are not a get rich quick scheme