Started inventory of my Russia Stamps to find out I need to know how paper (stamp) is "laid".....horizontally or vertically. Taking this SC # 28 from Russia, I have much difficulty, in the light, with my magnifier (my 2MP 1000X 8LED USB Portable Digital Microscope Endoscope Camera is not in yet)Your help is always appreciated https://en.wikipedia.org/wiki/Posta..._paper_terms
There is no such thing as LAID paper - at least as far as machine-made paper is concerned.
The bars you see have been applied in a separate process later on - you can feel them as in pre-war Polish recess stamps - or are part of the watermark apllied by a dandy-roll. The Russians are likely to have been part of the watermark!
In the 1850-1939 period ALL stamps basically have the impression of the sieve with a linenbinding resulting in what was show here above as "wove". The "laid" next to it was also the result of a symmetrical linenbinding with e bars applied in a later stage.
Since 1938 you can find stamp paper produced with a sieve thast has an asymmetrical twill binding.
What is the best method to identify the type of paper, 1) Ronson fluid or watermark fluid 2)Microscope 3) looking at the back of stamp in light at various angles. I have the Large Queen book by Duckworth with illustrations of various type of papers. At times, it is not that easy as it sounds, incl the thickness !