What were banker/accountant armbands called and what were they for?

Question

You know, in the old movies while they were working away by their green desk light bankers wore those leather straps around their arms. What were they called, and what were they for? Thanks!

Answer 1

They were called sleeve protectors. They held up or covered the man's sleeve so it would not get stained with the ink used. It was easier to keep clean that way.