458. Adding a Corner
Tzitzis 1:16
Similarly (to the case in 1:15), if a person put tzitzis on a three-cornered garment and then he added a fourth corner and put tzitzis on it, all of the tzitzis are invalid. Deuteronomy 22:12 says, “Make fringes” – make them, do not repurpose those that were made before.
Tzitzis 1:17
A garment may not be folded in half and then have tzitzis attached to the four corners in its folded state, unless it is completely sewn along even one side. (That is to say, it only has four corners when folded.)