Wow. This was decades ago and I'm not even sure some of the companies are around, but I looked up current paper companies and the only one that seems to register is Hammermill which looks like was absorbed into International Paper Company and maybe Strathmore?

To be honest, I was young and most likely came into contact with brands of paper rather than the manufacturers and the rise of personal computing basically annihilated a lot of the industry.

I wish I even knew what the book type was called, they sat somewhere in between swatch books and manufacturer trade magazines. They'd come out once or twice a year, have a variety of paper styles bound together in books of all kinds of sizes, and usually had beautiful somewhat non-sequitur photography or graphic art throughout to demonstrate what printed material would look like on the paper, often with a smattering of very high quality text. The sort of bizarre juxtaposition of these paper products and this beautiful graphic design was an appeal to itself.

My favorite book was one that featured photographs of ancient and vintage childrens toys and games (I was a kid) and some informational text about each.

edit I found these two examples

a modern example (at least the cover, I don't know what's inside) https://www.friesens.com/blog/new-colour-printing-paper-samp...

and this one from the early 1900s (samples start on page 33 of the book) - https://archive.org/details/directadvertisin1921pape/page/n8...

The contents of the older one has the DNA of the books I remember. The same kind of rambling text, then the paper samples with the state of the art printing and graphic design. By the 1980s these had taken on a more pop art style that was a bit like a more serious and toned down early Wired magazine house style.