The Rab Mythic 400 is part of the British brand’s premium range aimed at alpinists and backpackers who desire low weight and impeccable quality. It weighs in at less than 25oz, yet is packed with 900 fill power (FP) goose down that has been treated with Nikwax Fluorocarbon-Free Hydrophobic Finish in a bid to improve durability in harsh conditions. The range-topping materials do come at a cost; with a list price of $650 (US) / £560 (UK), the Mythic 400 firmly in the high-end category.
The bag is made with a recycled Atmos fabric shell, which is lightweight, windproof and highly water-resistant. The fabric is made from a 10D recycled nylon, and is waterproofed with a fluorocarbon-free (Durable Water Repellent) treatment. This commitment to sustainability is becoming a key focus for Rab, with the manufacturer claiming that 38% of the bag’s materials come from recycled sources.
The move away from traditional PFAS (perfluoroalkyl and polyfluoroalkyl substances) in favor of more eco-friendly alternatives is something to be applauded. The Mythic 400 has a trapezoidal baffle construction which is chevroned in shape, which Rab say is all in aid of keeping the down more during use. This results in a usable temperature rating of 21°F (-6°C), putting the Mythic 400 firmly in the category.
On the left side of the bag, you’ll find a half-length YKK zipper, which, while saving weight, can feel restrictive in terms of ventilation and accessibility. Similarly, the tapered design is i.
