Question on proof papers

coinpictures

I have an R3a that, upon closer examination, I believe may be a trial color proof rather than an actual R3a, but I'm not entirely sure. The color is appropriate, but the paper is very thin, almost translucent. I know the very early paper of many of the imperfs was very thin, especially on the $5 and $10 denominations.

I see references in Scott to "bond" and "india" papers used for the proofs and trial color proofs, but I need a bit more description and context...

Thanks.

covers

can't see your picture - if unused, almost certainly a proof.

coinpictures

Sorry, haven't scanned it in yet. Will try to get to it this weekend. Thanks.