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.