Unbleached traditional linen from Dorr Mills is one of my favourite backings for hooking as it works beautifully with yarn and fine wool fabric strips (5 cut and under).
It is a tighter weave than primitive linen with 13x13 threads per inch but has the same soft feel.
Half yard: 36" by 29.5"
Yard: 36" by 59"
Custom sizes available as well, just let us know what you need!