Arc'teryx Atom jackets: history and which one to buy

The Atom is Arc'teryx's best-known insulated jacket. It's not a Gore-Tex shell. It's a lightweight synthetic mid-layer you can wear on its own, and it's one of the most popular pieces on the preloved market.

Where it came from

The Atom family started as a small range of three styles and grew into a full collection. The idea was simple: synthetic insulation, with breathable stretch fleece panels in the places you sweat most, so it stays warm without overheating.

Atom LT

The foundation piece. It uses lightweight Coreloft insulation, 60g, with Polartec Power Stretch panels for ventilation. It's soft, warm, breathable, light and packs small. The Atom LT is the all-year-round one, which is why it's so popular. For winter 2014-15 the Atom LT Hoody got a rear drawcord on the hood for a snugger fit.

Atom AR

Arc'teryx added the Atom AR in winter 2014-15, replacing the older SV style. It's warmer, with three levels of insulation: 120g in the core, 80g under the arms and 60g in the hood, so it works as a mid-layer or an outer layer. It's the winter choice.

Atom SL

The lightest. It's insulated through the body only, with mesh-lined sleeves, so it's like a vest with windbreaker sleeves and hood. At around 280g, compared with about 370g for the Atom Hoody, it suits high-effort days in spring, summer and autumn. It's the summer one.

Heavier versions

Arc'teryx also offers warmer Atom styles for the coldest conditions, including an SV with 120g Coreloft and a Heavyweight with insulation throughout the sleeves and hood.

Which one?

• Atom LT: all-year mid-layer or light jacket.
• Atom SL: summer and high-output days.
• Atom AR: winter warmth.

Every Atom we sell is authenticated and photographed by us. Have one you're unsure about? We'll check it for £1.49. Read more: the Arc'teryx story.