What revived fabric means here
Bedsheets, clothes, and blankets that still have cloth worth sewing.
Little Runa does not start with a bolt of new cloth. A piece begins with something that was already used: a bedsheet, a garment, a blanket.
What can be saved is washed, looked at, and cut again. Stains and thin spots are left behind. The rest becomes a dress, a collar, a sleeve.