The sheer scale of this year's Macmillan Art Show is breathtaking.

Numbers stack up alongside artworks in equal measure. This year, the annual Glasgow-based charity sale of paintings, ceramics, glass, sculpture and jewellery features over 700 works by around 300 artists. The members of the founding Glasgow 84 Committee (a group of volunteers, some of whom organised the first shows in their front rooms back in the 1980s) have raised almost £2.8 million for Macmillan Cancer Support in the 30 years the show has been running. According to new co-ordinator, Carol Dunbar, the aim now is to break through the £3m barrier.

"We have introduced some new features," she explains. "One of them is Generous Brushstrokes, which sees 49 artists giving one artwork as a 100% donation, waiving the standard 50/50 split." Artists in this new section include well-kent names such as Muriel Barclay, Robert Kelsey, Marion Drummond, Georgina MacMaster and Gordon Wilson.

Another highlight is the presence of a pair of bronze maquettes of Andy Scott's world-famous Kelpies, who rise up out of the gloaming at the Helix Development in Falkirk. The wee Kelpies have been donated by the artist and will be sold by silent auction, with interested parties placing their offer into a 'Kelpie Chest'. The winning bidder will be revealed at the end of the show next Sunday. There is also a beautiful large oil painting, Restaurant Gigondas, Provence, by Jennifer Irvine which is up for grabs as a raffle prize.

The exhibition was formally opened at last night's Sponsors' Preview evening by BBC Scotland news doyenne, Jackie Bird. Today is the Previous Purchasers' Preview, and tomorrow, for the first time, the show opens to the public.

There is work here to suit all budgets, from a ceramic jar by Anna Brown (£30) to a large oil painting by modern Scottish master, Glen Scouller, titled Bluebells And Wild Gaelic, Colonsay (£8000).

And it's not all about cash transactions: tomorrow, Gordon Wilson and Marion Drummond will give demonstrations and discuss their inspiration and technique. Drummond paints in oils with her fingers and rags, so this should provide a fascinating insight.

The loyalty shown by artists and by the art-buying public towards the Macmillan Art Show is the stuff of legend. "Some of the artists have been with us for 30 years," Dunbar explains. "They want to participate because it's Macmillan. Visitors have the same feeling so we're all on a good grounding. That is the key. Our oldest artist, William Ower Brown, exhibits every year. He is in his 90s, while our youngest is a Glasgow School of Art graduate from Helensburgh, Thomas Cameron."

In the course of the next seven days, it's expected that around 4,000 people will make their way to retail giant M&Co's Inchinnan HQ to browse around its airy Caledonia Galleries space. This is a feel-good exhibition to warm the soul and raise money for a cause which touches us all.

Macmillan Art Show 2014, Caledonia Galleries, M&Co, 5 Inchinnan Drive, Inchinnan, Renfrew (www.macmillanglasgowartshow.com) from tomorrow until November 9