It is the 10th anniversary of the launch of this popular event and the CAS has pulled out all the stops. Last year, collectors started queuing at 7.45am in the hope of being the first in to snap up the cut-price masterpieces. It may be even earlier this year.
The market comprises a show of works by 125 artists specially selected by the staff of the society; the CAS stamp of approval encourages buyers who do not have the confidence to back their own taste in the contemporary jungle.
All the paintings, drawings and sculptures on offer are priced at or below pounds 1,750, and start at about pounds 100. Buyers can take away their purchases on the spot, providing space for new works to go on show. Last year, 507 works were sold to 312 buyers for a total of pounds 240,958 over the six days.
To mark the 10th anniversary, there are more famous names than ever. Anthony Caro drawings were offered at the first markets but then became too pricey; there are four this year at about pounds 1,750 each. The two small geometric gouaches by Bridget Riley are also priced at the top limit, as is the Therese Oulton oil. Gillian Ayres has two colourful abstracts at pounds 1,750 and pounds 1,645, and there are two Sandra Blows at pounds 1,250 each.
But the real snips of the event are the 15 different head-and- shoulders statuettes made entirely out of matches by David Mach. He calls them Lucifers and has made strikingly colourful images by using matches with differently coloured ends; they stand five inches high and cost pounds 412 each.
The buff-coloured tiles decorated in relief with fabulous beasts by Dhruva Mistry are also a great buy at pounds 300; there are four for sale, each a one-off, although the images owe their very clear definition to having been stamped from a mould.
The market organisers make a great effort to search out new artists whose work they consider admirable. The small brightly coloured abstracts by Andrea Rausch, just out of the Royal College, are priced at pounds 100 each. She has an attractive trick of continuing the painting on the canvas which is wrapped round the stretcher, thus making her paintings three-dimensional.
Another new arrival is Iwan Gwyn Parry, who also paints small squares on the edge of abstraction; they look as if they might be details from paintings by Francis Bacon - you feel you can nearly recognise the subject.
The Contemporary Art Society was founded in 1910 with the purpose of buying contemporary art and giving it to museums; there are now 50 museums eligible for donations. The society generates the income for buying art through two principal activities, advising companies on the purchase of art to decorate their offices and the annual market at Smith's galleries. It gets a 30 per cent commission on all sales.