A floating, two-toned chiffon scarf draped across a shelf seems on the brink of fluttering right off as you walk past, while a flock of magpies could burst into song at any minute.

Double-takes and long, searching looks are the norm as you pick your way carefully through the latest offerings of the Ranamok Glass Prize. From shoes encased in glass to an oversized box of matches, an iceberg encased in a block of blue ocean, a necklace of possum skulls, floating white mushrooms and a delicate bowl made of woven lines that cast a lacy shadow on the plinth – the possibilities for glass seem endless. And when you see the winning entry, an aged oriental carpet that even, somehow, has footprints showing through its glowing gold thread, it seems impossible that it could be made from the same stuff as the vivid red pears topped by a single magpie nearby.

This madcap pushing of boundaries has always been the point of the Ranamok - to run amok.

But now, after 20 years, the Ranamok has run its own course, and co-founders Maureen Cahill and Andy Plummer are winding things up. Both glass artists themselves, they believe their work is done, and it’s time to focus on their own practice.

For Plummer, it seems a lifetime ago that he experienced what he still describes as a transcendent experience, during his first class in a short course in glass making at the Sydney College of the Arts in the early 1990s. It was there that he met Maureen Cahill, an artist who established Australia’s first glass course in 1978 (Canberra’s course was established four years later), and the two decided to establish a prize for glass artists. Plummer was a mining executive, and was keen to develop a focal point in the arts for corporations in his sector to champion through funding. And Cahill wanted an outlet for glass artists at all levels, with no prescription or brief as to what could be entered.

Over the years the Ranamok has flourished, along with many of the careers of its winners and finalists whose work is exhibited and toured around the country.

Head of the Glass Workshop at the ANU School of Art, Richard Whitely, who is also a finalist in this year’s prize, says the Ranamok has performed an important function over the years.

“For the past 20 years, it has been able to bring a focus, not only within the sector, but draw others to what contemporary glass can be in all its diversity,” he says.

“Glass has so many different material approaches and idea approaches, it can be seen as more associated with the craft of the fine arts. And its elasticity, both in technique and in thematic approaches, allows such a range of different ideas to be manifest within the material.”

But he agrees with Cahill and Plummer that the Ranamok has done its job, and done it well.

“It’s brought a sense of attention to the material and it’s now time for something else to come forward to take the sector in another direction,” he says.

“I think it’s served its purpose really well. It is sad it is finishing but I think it’s also timely.”

For Cahill and Plummer, there’s something appealling about ending their run on a nice round number, at a time when both are stepping up their own practice. Cahill exhibits regularly, has a large work hanging in Parliament House here in Canberra, and runs the Glass Artists’ Gallery in Glebe, Sydney.

Plummer, meanwhile, still considers himself an “emerging artist” and says he has had enough of living vicariously through the work of other artists.

“I’ve had sort of a virtual practice. I know how to do it and I know a lot of people, I see a lot of interesting ideas and I’ve always wanted to do my own thing,” he says.

“I see people’s work and I admire a lot of it, but I’m not capable of doing that. When people talk about visual designers and artists finding their voice, I always thought that was a cliché, but it’s actually not, I understand it now.”

And now, at the age of 64, having retired from corporate life, he says it’s time for him to step up his own work and “make it count”, and prepare for his first exhibition next year.

He points out that the prize is also surprisingly time-consuming and expensive to run, costing around $150,000 a year, and as a non-profit, generating sponsorship has always been a major undertaking.

And while he and Cahill initially considered handing the prize over to someone else to run, they have decided they are too attached to its ethos to hand it over.

“I know how much effort and how much time and how much money it takes to make this work. And notwithstanding people having the best intentions, the concern that I have is that I’m so indelibly attached to the prize and the name Ranamok, that I’m just concerned about reputational issues, that people won’t do as good a job as we have done,” Plummer says.

“But if somebody is keen to do it, I’m very happy to help them in terms of how to do and what I did and all of that, very happy to provide that kind of advice to people. There’s no dog in the manger talk and there’s plenty of room out there for everybody, and I hope somebody does it, frankly.”

The prize will also live on in one of the country’s most important national collections: Cahill and Plummer will donate the Ranamok acquisitive collection – all the prize winners for the past 20 years, which have, until now, been packed away in crates – to the National Gallery of Australia.

It’s yet another accolade to those artists who have embraced the prize’s edict, to run amok and see what glass can do.

For full list of finalists and more information visit: ranamok.com