I’ve stated making my own stationery (or upcycling old book pages into new stationery…)
Here’s my how-to tutorial 
If you have a keep eye you’ll notice these pictures are from different sets because I missed documenting a few the first go around 
Firstly tape your pages down to a flat surface (I like to use painters tape):
Apply two coats of white gesso, no need for the first coat to dry:
Let the gesso dry then do a quick wash with watercolor. For this set I used burnt sienna first (I’ve also made sets with the same watercolor color for all the layers and it looks fine 
). Before the paint dries use a cloth to blot the excess water off:
Let that dry then add 1-2 coats of your top color using the same method. You can also use plain water if the color becomes too concentrated. I find it best to let it sit for a little while before blotting but you might want to experiment on your own to see what works for you:
Carefully remove the tape once the pages are dry. Expect the edges to tear in places. You could trim the raw edges off, but I like to leave them a little rough.
Some detail shots:
Thanks for looking! 
though I’ve been doing a lot with them, somehow making stationery didn’t cross my mind!