Arches Platine's basic parent sheet is nominally 22x30, but is actually at least a quarter of an inch oversize on the short dimension because of the feathery deckle there. Shipping supplies however, are precision cut to 11x14 inches, if that's the item you order from Uline. So, as I work on the TOP Platinum Print Offer orders, I can't simply cut the sheets into quarters. I have to quarter them in a way that ends up with printing sheets that are exactly 11x14, and that leaves a certain amount of wastage.
I've never done any handmade papermaking, but I've seen it demonstrated and have had contact with folks who do it as part of the Artist Book milieu. You can also make your own paper for Pt/Pd printing though that's not a place I'm interested to go. I know that for many, making your own artisanal paper begins with finding scraps of "rag" paper (meaning cotton, not wood pulp) to sort of melt down and begin the home brew. Well, these scraps are from about the most primo all-cotton paper imaginable (25 sheets ships in at just short of $200) so if anyone reading here has something better to do with this than throw it in the recycle with the cardboard, let me know.
Tech details for anyone interested. Cutting down paper for Pt/Pd printing is very picky. If you use a knife and metal straightedge, or the superb RolaTrim cutter I use with the roll paper output of my big HP-Z3200, or scissors, all these tools have a metal-on-metal action that is apt to scatter microscopic particles of metal. What does Pt/Pd-coated paper and developer think of those particles? Yum! Attack! Dense black spots in the print.
Tearing it doesn't work either with Platine, though it's OK with some other papers. With this stuff, torn sheets seem to bleed tons of cellulose into the developer, which I don't need to deal with. To get a clean cut, I simply use my matt cutter, with the flat blade intended for cutting down parent sheets of matt board before you cut the windows. The blade floats about an eighth of an inch from the guide rail, held by the slot in the tool. So it touches nothing but the paper, can't make contamination, and is easy to use.