Feltwyn sells one idea: warmth is a measurable quantity, and almost every blanket is sold without ever naming it. Their answer is printed on the label in grams per square metre — 620, heavier than a duvet, closer to a rug than to the thin woven throws it sits beside on the shelf.
The construction is old on purpose. A tight diagonal twill rather than a knit, because a knit opens when you stretch it and a twill holds. Crimped wool fibre that keeps still air in place — the air is the insulation, and the wool is only the scaffolding that stops it moving.
It makes for a slow business. Heavy cloth is expensive to weave and expensive to ship, and Feltwyn has never released a lightweight version to widen the range. The whole company rests on the belief that people who are genuinely cold will pay for the weight.