Identifying Cut Squares And Entires

With the usual caveats relating to the difficulty in identifying colors (in this case paper color) across the web, I believe you have a Die 1 on white, U411.

Couple questions.
1. Is the paper laid or wove? I'm told the Scott catalogs now (2017 edition) recognize the difference. The UPSS catalogs always did.
2. What is the watermark in the paper? Just describe it, if you don't have a catalog that lists them.
3. We can figure out the size of the envelope by measuring the size of the stamp on the screen, but we need a look at the back to determine the knife. Can you give us a scan of the back?

11/12/2016: Opinion changed. See down thread.

huh. I'm not sure how to describe the watermark ... I'm not even sure I know what to look for. I have ordered copies of Postal Stationary catalogs from UPSS ...

here's the back


and here's an image overlaid by another U411 (I think) that is rather obviously white (at least to me). Your'e suggesting that these are the same color paper? Is there that much variety in color?

Based on seeing the two envelopes together, I'm changing my opinion to buff.

This is a good example of how colors can fool you when there has been a translation from the original paper to an internal format (JPEG), then to an external format (screen R,G,B) (or print CMYK), then to the physical characteristics of the specific output medium.