There has been some recent discussion regarding whether a first issue revenue stamp on laid paper might be genuine.
The first step in getting any previously-unknown paper variety of just about any back of the book stamp is to get the item certified.
Having an additional confirming copy (or copies) of the new variety obviously certainly helps.
Being able to quote an entry from old philatelic literature that mentions your variety helps quite a bit, but this can be difficult to find.
Even then, your new discovery may or may not get eventually included in the Scott Specialized Catalog.
Shown below is an example of a paper variety of OX1 that is still unlisted in Scott.
It may not ever be listed, mostly because it is not a "dramatic" variety, such as a double impression or printed on both sides, and it is a variety of an infrequently collected area of stamps.
As we all know, most areas of the non-postage sections get very infrequent updating, unless there is an enthusiastic dealer or collector that "pushes" for the revision.
Still, to an official seal collector like myself, this seal seems to be the only known copy of this variety, and it remains highly prized for its unusualness.
Jim
The thin paper variety, front and back. The paper is as thin as tissue paper, but not as fragile, and is more translucent. At one time, I considered it pelure paper, but this paper is not as "oily" as pelure paper. You can almost read through it.



A normal OX1, front and back:

