Exodus 36:10 (KJV)

And every wise hearted man among them that wrought the work of the tabernacle made ten curtains of fine twined linen, and blue, and purple, and scarlet: with cherubims of cunning work made he them.

The length of one curtain was twenty and eight cubits, and the breadth of one curtain four cubits: the curtains were all of one size.

And he coupled the five curtains one unto another: and the other five curtains he coupled one unto another.

And he made loops of blue on the edge of one curtain from the selvedge in the coupling: likewise he made in the uttermost side of another curtain, in the coupling of the second.

Fifty loops made he in one curtain, and fifty loops made he in the edge of the curtain which was in the coupling of the second: the loops held one curtain to another.