Restoration question,..bolt finish "S"..

[d.j. moordigian]

I have this question about the bolt finish "S" from the "Standard Hardware"
book. The "S" in the book states that it is "Plain",..

What finish/color is "plain"?
1. Is it after the fastener was made,..bluish/black for Steel?
2. Were the parts "tumbled" too a bright/flat Steel finish?
3. Some kind of acid bath finish,..semi-bright with rust spots?

I'm sure there are other combinations.

NO guessing,...I'd like to hear from some of the fella's of the Judging Standards committee that knows..

Thanks,
Dudley