ThermoPlume fills the air in the snow globe in Newcastle Exhibition Park. Photo: Bob Smith/grough

It’s a cool, breezy day on Tyneside and on Newcastle’s Exhibition Park’s lake the resident swans are doing what swans do: swimming around with a passing glower at the gathering of visitors on its shores.

Or perhaps the fowl are confused for, hanging on the wind are feathery wisps and the humans outside the former Palace of Arts appear to have grown plumage.

The group has just stepped out of a giant snow globe where outdoors brand Montane and insulation manufacturer PrimaLoft have been demonstrating the properties of the latest ThermoPlume material.

Montane's head of marketing Terry Stephenson welcomes us to Tyneside. Photo: Bob Smith/grough

For years, down was king when it came to producing insulated jackets for outdoors enthusiasts, but slowly synthetic materials have been threatening to take the crown. Goose and duck down still reign when it comes to weight and packability, but they are expensive, perform badly when wet or damp and there are concerns among many about the use of what is essentially a by-product of the food industry.

Down prices also fluctuate weekly, which makes it difficult for outdoors brands to cost their garment manufacture.

Treating down with hydrophobic chemicals helps limit the collapse in lofting that pretty much destroys the material’s insulating properties when wet, but for real performance in the damp, synthetic material can be viewed as having the upper hand.

Lottie Watkinson demonstrates the qualities of a Phoenix Jacket. Photo: Bob Smith/grough

Northumberland-based brand Montane and US company PrimaLoft invited outdoors journalists to the North-East of England to demonstrate the new material and further enhanced the invitation by staging the event in the Wylam Brewery, which now occupies the former museum in the park.

Terry Stephenson, head of marketing for Montane, explained the brand was the first in the UK to use the new PrimaLoft Black Insulation ThermoPlume. His colleague Lottie Watkinson, product director for the company, which is about to celebrate its 25th anniversary, said Montane has a small, nimble development team which has worked with PrimaLoft for 15 years.

The two companies often work together as practical test partners. Ms Watkinson said Montane’s speciality was innovative, lightweight and breathable gear.

The women’s Phoenix Jacket and the men’s Icarus are now appearing in outdoor retailers and both use the new ThermoPlume filling.

Wim Neels explains the properties of the new PrimaLoft material. Photo: Bob Smith/grough

PrimaLoft’s European PR manager Florian Schneiderbanger had flown in to the event from Munich and his colleague Wim Neels, sales manager for the UK, Denmark and Benelux, joined him from his Belgium home to explain the advantages of the new product ingredient.

ThermoPlume looks very much like down and shares many of its properties, Mr Neels said. It acts like down within the baffles but its polyester make-up meant it was water-resistant.

He said: “ThermoPlume has the structure of, and feels like down. It travels within the jacket baffles but without cold spots.

ThermoPlume has a feel similar to down. Photo: Bob Smith/grough

“It has superior softness and very good moisture management. It will keep you warm longer than a down jacket in the wet.”

Another advantage is that it can be blown into jacket baffles during manufacture, using the same machines as those used for down, giving better consistency.

Mr Neels said: “PrimaLoft is seeking the ‘holy grail’ of insulation, to develop a synthetic blowable equivalent to 850 fill-power down, to mimic down in feel and compressibility. We’re not there yet but we’re getting closer every day.”

PrimaLoft’s Black Insulation ThermoPlume’s silky tufts of fibre provide an equivalent wamrth to 550 fill-power down – in the mid-range for insulation. Montane’s

Journalists emerge from the snow globe with a covering of ThermoPlume. Photo: Bob Smith/grough

Icarus and Phoenix have been designed with mountain walking and trekking in mind, though the brand also sees a use for mountaineers, Alpine climbers and ski tourers.

Comprehensively informed, we head out into the park where the giant inflatable snow globe has been installed, containing stands with the Montane jackets and a fair amount of the ThermoPlume filling.

As the fans are turned on, the synthetic filling fills the interior of the globe. The ThermoPlume certainly has a very soft feel and could easily pass for feathers. Suitably clothed in Montane jackets and covered in PrimaLoft insulation, we emerge to baffled gazes from families passing by.

Back inside the relative sanity of the venue, Wylam Brewery has produced two special ales, Icarus and Phoenix to mark the launch.

A walk alongside Hadrian's Wall in very autumnal weather provided a good test of the Montane jacket's properties. Photo: Bob Smith/grough

The following day, and with completely clear heads, we head west out of Newcastle under darkening skies. Our destination is Hadrian’s Wall and The Sill, the new visitor centre from where we will walk, wearing our new insulated jackets.

Conditions are perfect for testing the Icarus: it’s wild, windy and wet. The rain varies from torrential to showery. Some choose to use the Montane jackets as outerwear; others use the ThermoPlume garments under waterproof shells.

I chose the latter and, with a Montane Primino baselayer, the Icarus jacket and a waterproof shell, the walk to Crag Lough and back was completed in comfort. Breathability was good and the Icarus kept me warm on a fairly foul day in the Northumberland countryside. Those who chose to wear the Montane jackets as outerwear reported they had performed well. The shell of the jackets uses Pertex Quantum Eco lightweight, which is windproof and also benefits from a durable water repellency.

The Montane Phoenix women's jacket uses ThermoPlume insulation

If the technology continues to improve it should only be a matter of time before PrimaLoft’s scientists come up with a real contender to challenge 850 fill-power down jackets.

In the meantime, a reasonable £140 will get you an Icarus or Phoenix that is ideal for keeping you warm while on the move in typical British conditions – wet, cool and windy.

We’ll be giving the Montane Icarus a full test in the near future.

• grough went to Newcastle and Northumberland as the guest of PrimaLoft and Montane.