To properly perform its function a floorcovering must, above all, be constructed of durable materials. What your carpet is made of is of more importance to you than the technicalities of its weave.
Wool
The most widely used material in the floorcoverings of every era and every people has always been wool. No other natural fiber can approach it for durability, warmth, resilience and resistance to soil.
Though sheep are raised all over the world, it is only certain breeds reared in rigorous climates that have fleeces long, tough and springy enough for use underfoot.
American wool is too soft and fine for carpet weaving, so all of the wools we use are imported from other parts of the world.
Because they are not competitive with our domestic product, they come into this country duty free, under bond to be used only for floorcoverings.