Harris Tweed must, by law, be made by home weavers on non-electric looms, in the weavers’ own homes on the Outer Hebrides Islands:

Harris Tweed® is a tweed which must, by law, be produced from yarn which is made from 100% pure new wool which has been dyed and spun in the Outer Hebrides of Scotland and woven by hand at homes of local islanders. It is the only fabric in the world to have its own Act of Parliament.

They saw the value of keeping the traditions alive, and even wrote it into law.