NET
21 No one sews a patch of unshrunk cloth on an old garment; otherwise, the patch pulls away from it, the new from the old, and the tear becomes worse.
Darby
21 No one sews a patch of new cloth on an old garment: otherwise its new filling-up takes from the old [stuff], and there is a worse rent.
KJV
21 “No man also seweth a piece of new cloth on an old garment: else the new piece that filled it up taketh away from the old, and the rent is made worse.”