Are tzitzit strings made from low-quality wool (caught on thorns, plucked from the animal, or warp remnants) valid?

Synopsis

All authorities agree such strings are invalid — not because of an intrinsic disqualification, but because using degraded materials is a disgrace to the mitzvah. The Magen Avraham and Aruch HaShulchan add that material so poor that no garment could be made from it is also technically invalid.

Early Acharonim
Lenient
Strict
Lesser cited
Major authority

Discussion

Discussion coming soon.

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