Hi!Had the same issue but playing one a different platform ,the recipe calls for cardboard but is then substituted.I think it was a Mounted Belt I had to make.
I don't recall what the lower level furniture factory has available, but both paper and cardboard do come out of the Timberworks bldg (which also handles all the furniture the old furniture factory made).
It's more likely they just added it, I think. Because things you don't have the level for still show the recipe, their create button is just grayed and it'll have some text on it that tells you the available date. Either way tho, good, glad you got it hehehe
Furniture factory paper (first) takes 3 boards, 1 saw from Smithy, to make 1 paper but you will need 3 of those to make cardboard once you combine them with 6 glue to make 1 piece of cardboard. I want a spin your luck with cardboard on it now.