Price: £88 (on sale) RRP £110 – Self purchased – not supplied or sponsored by Thrudark.
Spring/Summer 2025 were spectacularly warm and sunny and I had been looking around for a base layer that could help with the sweltering heat. I took a chance on the ThruDark Oryon Delta, mainly because I liked how it looked and the claims of thermal regulation seemed interesting.
The Oryon Delta is first and foremost a warm weather base layer. It has a “waffle” texture and is made from Polartec Delta fabric. The idea behind the waffle texture is that the garment has a lower surface area of contact with your skin – helping to avoid that dreaded clammy feeling where your base layer gets saturated and clings to you like soggy kitchen roll.
The above selfie was taken hastily during a solo trip on a very hot day. You can see the waffle texture, and the two handy chest pockets. On one of my first trips with this base layer I headed over the summits of Commedagh, Corragh, Slievenaglogh and Bearnagh – then back, in very hot weather. The base layer didn’t get clammy, and a good breeze over the fabric was always enough to shift any sweat.
Many of my summer trips have involved starting at Donard Park and heading up through Donard Wood and the glen river trail to get into the hills. It’s quick and easy to get to with little driving, but the wood is very closed in and it can get a bit clammy racing up through it carrying a camping pack. The Oryon Delta base layer certainly helped with this. I never felt like the sweat from this part of the walk remained in the garment for long, once I’d get above the trees and into the breeze, it would always dry off nicely.
In the above image you can clearly see the long zip, this is great for some extra airflow when you need it.
The long sleeves come in handy for avoiding sunburn, although I regularly roll them up, as I’m not a fan of keeping my forearms covered – avoiding sunburn being the only reason I would.
The Oryon delta doesn’t have any specific odour-killing features, but I found it managed to stay fresh, perhaps because it tends to dry out pretty quickly. It’s also relatively hardy – it has seen quite a few hours under a rucksack, and hasn’t bobbled up or faded on me yet.
One big downside to this base layer is of course the price. The long sleeved version is currently reduced to £88, but the full RRP is £110. Over £100 is a lot of coin to part with for a base layer. Given how frequently I get out in the hills and the fact that it keeps me comfortable during exertion in the heat – I’m happy enough to take the £88 hit – knowing it’ll see a huge amount of use.
I have no durability concerns, unlike other thermoregulating garments that resist odour buildup – this one isn’t made of Merino wool. I’ve used Merino based base layers before and they’re fantastic – but they get ripped to shreds in no time. This alternative seems a lot more robust.
I’ve also continued to wear it as the weather has started to cool into autumn. I’m not a huge fan of insulating base layers and don’t use them in winter. It’s the one layer you can’t (or at least shouldn’t!) be taking off, If I want to insulate, it’ll be with a mid layer, and almost always when I’m not moving.
In conclusion this is a high performing base layer top that helps to keep you fresh when on the move on hot days. I’ll continue to update the review as time goes on. If you can stomach its eye watering price tag, I think you’ll find the Oryon Delta base layer to be worth it.
Click here to view the Oryon Delta base layer directly at Thrudark’s official online store.