Related su Esodo 26:41

The curtain is 40 cubits long and 20 cubits wide, It was weaves “of blue and crimson and byssus, fine linen, goats’ hair - work of art weaving”. A second [curtain] there was, 20 cubits long and 10 cubits wide. It was woven “of blue and crimson and byssus, fine linen, goats’ hair - work of art weaving” and was spread out over the entrance to the sanctuary from outside R. Judah says: The one that was taken out from within was folded double and fourfold, and spread it [then] from without over the entrance to the sanctuary. It was said to him: Can something that has served the purpose of what is strictly holy serve for what is less holy?

Another explanation: In relation to this it is written: “art weaving work” and in relation to that it is written: ”color weaving work”. R. Nehemya says: art weaving work [means] two faces, and knitting work [means] one face. Rather, that [curtain] which was taken out from within was folded two and four times and spread out in the upper part opposite to the lower, for it is said: “And the veil shall separate you etc.”.