Scott U436f Entire With No Wmk? Help!

I can't find the water mark on this envelope. size 10 knife LB 59W

.US Beginner, just a thought.
If you have privately printed stationery as does GB,
would the paper be necessarily watermarked?

I can't tell if the paper is regular or extra quality from a scan but probably wm 35 or 36 based on the date of usage. Watermark probably disappeared when the window was cut out. There is also a possibility of watermarks 31 through 33 either lost with the window or a really worn dandy wheel in the paper manufacture. A check of the UPSS catalog reduces the watermark choices to 31, 33, or 36. Based on the date of use, I would choose 36.

Well it seems odd because I have 3 more window envelopes and they all have at least 3 watermarks showing.Thats why I thought this one would show at least one or partially two watermarks.

I think I found part of it. under window rotated to about 8 oclock with part of the top back of "S" showing directly under window starting down from postmark and a little to the left. then just below that a fine back leg of the "U". I traced the watermark from another envelope and laid it over. best I could come up with. I also see the top tip of the front leg of the "U". Cant see any date.

Based on your description it could be wm 33 or wm 36. Based, again, on the date in the cancel, I would go with wm 36.