I think this idea is brilliant.

“Wool Filler for mending holes in textiles was born out of a need to repair a hole in a woolen cardigan. The edges of such holes are rarely clean-cut and they are often surrounded by ladders, fraying or worn patches. The differences in thickness and the openness of the structure make felt the ideal solution for mending. Felt, being non-woven, attaches easily to any open structure. Fillers made for materials like wood consist of fibres and a chemical binder. Felt is different: it attaches mechanically by means of minuscule scales. Where once there was a hole, there’s now a new piece of fabric.”

Well loved cardigan… rescued!

(via here)