3,950. Requirements of the Bigdei Kehunah

Hilchos Klei HaMikdash 8:3

“White garments” refers to the four garments that the Kohein Gadol wears on Yom Kippur: the tunic, breeches, a sash and a turban. These are all white, of six-ply thread and made solely of linen. A Kohein Gadol had two other tunics for Yom Kippur use, one of which would be worn in the morning and the other in the afternoon. Each of these cost thirty maneh and was purchased using community money. If the Kohein Gadol wanted to purchase more expensive tunics, he could add money from his own pocket. He had to consecrate the extra money, after which it could be used to make the tunics.

Hilchos Klei HaMikdash 8:4

There is a mitzvah for kohanic garments to be new and attractive, as well as to hang low like the garments of important people. This is derived from Exodus 28:2, which says they must be “for honor and for beauty.” If the garments were dirty, ripped, too long, too short or pulled up by the sash, and a kohein served while wearing them, the service is invalid. If the garments were worn out, or if they were too long but he pulled them up with the sash to make them the right length, his service is valid.