'Printmaking is a medium comprising lithography, etching, drypoint, woodcut, linoleum cut and screenprints,' says Mary Bartow, head of Sotheby's New York's prints department. 'While original prints are multiples rather than being unique pieces, they are not reproductions.

'[They] are customarily well documented, the price history can be traced and prints are generally more affordable than unique objects. For these reasons, new collectors find it an accessible market, one where they can feel comfortable buying.'

In March, Sotheby's in London held an auction of old master, modern and contemporary prints.

On the block were works from Bacon, Lichtenstein, Matisse, Miro and Warhol, among others. A Picasso print dated 1933 sold for just under US$10,000, while Rembrandt's Death of the Virgin from 1639 went for around US$4,000.

'Pieces of unique art have escalated in price, while prints remain relatively cheap and are much more stable,' says Anders Petterson of art market research firm ArtTactic. 'Had you bought a print of Takashi Murakami's Killer Pink in December 2007 for US$3,200, you could've sold it for US$9,600 in April 2010. The print market offers an affordable entry point for established as well as emerging artists.'

The key to a clever investment is understanding the printmaking art, says Kate Bryan, director of the Cat Street Gallery. Research of intricate technical aspects is essential.

'I would always say to buy an original work of art, something which was created to be a silkscreen or an engraving, rather than editions [duplicates] after a painting,' she says. 'There is also a danger of over-saturation in the market if an artist does not restrict the edition; ideally, the work should be around an edition of 100.'

Angela Li, of Contemporary by Angela Li, agrees: 'The smaller the better. Some prominent artists still work with 10 to 20 pieces for a print, and there are also great artists doing mono-prints - one-off pieces that are unique.'

Li herself is an avid collector, often seeing returns five to 10 times her initial investment within a few years of purchase. Much of that is due to a keen eye in terms of the piece's condition.

'Prints are works on paper, which means conservation and condition are critical,' says Bartow, who recommends keeping your prints in acid-free rag mats and away from direct sunlight. 'Improper storage can cause problems, which have problematic effects on a print's value.'

That sense of value is almost a taboo subject in the print market, the medium having not yet caught up with such monetary-based fine art as paintings or sculptures. Most collectors or connoisseurs will tell you to do it for the love, not the money, but every expert has recommendations in terms of bankable printmakers.

Li advises new collectors to focus on upcoming Asian artists, especially graduates from printmaking academies who are dedicated to their craft, such as Xu Bing, Su Xinping and Wang Yiqiong. Bryan says that there are many artists who 'put a lot of energy into their work', such as Peter Blake, Gavin Turk, Natasha Law and Jake & Dinos Chapman, and that the Asian market is also a safe investment as prices are low.

Sotheby's Bartow suggests printmakers who are on the rise: Serra and Lewitt, Ellsworth Kelly, Ed Ruscha, Donald Judd and Richard Estes, 'artists whose careers are long established, but whose printmaking works haven't received the attention due'.

ArtTactic's Petterson is a little more cautious: 'I would generally look for artists where prints are a part of the artist's normal output, and not only a commercial strategy for targeting the lower end of the market,' he says.

But prints have long been an important part of collecting and will continue to be, according to Bartow.

'When an artist's unique works command high prices, buyers are likely to turn to their prints as an affordable means of collecting,' she says. 'Prints continue to be a lively and accessible collecting category, and we expect this will be the case for years to come.'

THE BIG NUMBERS

Top five artistic prints sold at auction

US$2 million - Pablo Picasso, La Minotauromachie

Sold last year; another edition sold in 1990 for US$1.4 million

US$1.8 million - Edvard Munch, Vampire II

Sold in 2007; another edition sold last year for US$1.3 million

US$1.8 million - Edvard Munch, Madonna

Sold last year; another edition sold in 2006 for US$556,000

US$1.7 million - Pablo Picasso, La Femme Qui Pleure I

Sold last year; another edition sold in 2004 for $814,000

US$1.27 million - Edvard Munch, Two People, The Lonely Ones

Sold in 2006; another edition sold this year for US$50,000