I like to work on a bunch of mixed media pieces at a time, and I occasionally lose track of them, or can't figure out quite where to put them while thinking about what to do next. An old book (discarded/retired from use) is a terrific place to work and it allows me to keep track of where my various works-in-progress are, but it is also inspiring. I like how elements of the printed page may show in my final work and that when finished, the book is transformed into a completed art journal.
I choose a vintage hardback book that is a size and format that I like (not too small, not too large), and one that doesn't have too many pages. Kids books can work well for this. My local library sells discarded hardback books for $1, which is a great price for a journal. I still usually remove some pages and, if the pages are very thin, I may glue two pages together to make a stronger substrate for collage and paint.
A recycled book used for art-making is generally referred to as an "altered book." I think of mine as "altered book art journals."
I lightly gesso the pages so that some print still shows through and then I work in either single or double-page spreads. I usually leave the backside blank, as I like to allow for the possibility of removing pages later for sale or framing.
Here are some photos showing both prepared (blank) pages, and then a few images from my most recent altered book art journals.
If you'd like to see more altered book art, you can find many photos of them on-line, and on Instagram you can check out the account @oldbookrevivalists or the hashtag #oldbookrevivalists.