The artist is only revealed once the money is handed over

And their efforts are rewarded by fans queuing round the clock to get their hands on it.

But those hardy followers of art are taking a gamble on what they are purchasing.

Queue

The identity of the artist remains a secret until the time it is bought. The artist signs the picture on the back and it is only revealed once it is taken off display and given to its new owner.

Last year a women queued for two days mistakenly thinking she had picked a Damien Hirst. But she still went home happy as she bagged herself a Nick Park instead.

This year's big names also include fashion designers Zandra Rhodes, Prada and Manolo Blahnik, who is more famous for his shoes.

There is also work from RB Kitaj, Billy Childish and Julian Opie, the man behind the cover of Blur's greatest hits album.

The postcards go on display to the general public on Wednesday in the RCA gallery.

And for the first time in the event's history all 1,600 works will be displayed on the web ahead of the sale at David Bowie's art sponsorship site Bowieart.

Popular images make up a large section of the exhibition

The collection is an eclectic mix using all forms of media from photography to 3D sculpture.

There are topical designs with Osama bin Laden and New York as central themes in several.

There are witty ones such as number 225 which depicts Railtrack Headquarters as a jumbled mess.

Then there's the 'ironic' one in which the artist has simply drawn lines and a stamp to make it a postcard.

To the untrained eye there are also a few that look like squiggles in black biro on lined paper, similar to those adorning the workbooks of school pupils everywhere.

Discerning eye

Others are almost childlike in their design while many are very much in keeping with the cliches of "student art".

But for the more discerning eye there is the chance to invest in the future of art.

Pop art: Julian Opie created Blur's last album cover

There are some gems in there and there should be something to appeal to everyone from cute to abstract.

There are at least four that look like the work of Oscar-winner Nick Park, with pictures of Wallace, Gromit, Shaun the Sheep and some Creature Comforts.

But although the exhbition is not designed to trip people up, there is no telling whether they are Park orginals or painted by a student imitator.

Another example is a postcard with the words "Damien Hurst" (sic) written across it. Is this the man himself confusing matters or a clever student cashing in on his name?

Secrets curator Emily Sargant explained: "Some artists will design a postcard in their trademark style which will be clear to viewers.

"But others may use the opportunity to do something different.

Democratic

"Also some artists may be working in a smaller scale than usual, making it more difficult to recognise it."

She added: "The whole process is very democratic as all artists exhibit in the same scale and none of the works are singled out for special attention in the hanging process."

Flower power: Fans queue for hours to get their hands on their favourite work

Money from the sale goes towards bursaries for RCA students who are studying varied postgraduate courses such as fine art, applied art and communications.

So far �450,000 has been raised for student funds.

"For most people buying these postcards it is not about making a quick buck but being able to have such works of art in their own homes," added Ms Sargent.