This is a fun idea I would love to find time to do some day. This is shared by Diane (Belle33) in the forum. She has made and shared a lot of these over the years with us.
She writes: "I have made coloring books for my grandkids from digital books that I have made. I make the layout black and white, and then apply the sketch filter. You need to make some adjustments with hue/sat and delete some distracting details but it was worth the time. The kids loved the books. I left her face untouched, but it all could have been black and white. I bought an inexpensive binding machine (at Amazon.com) and binders and I do it all --designing, printing, and binding--at home. I always do rectangular scrapping so I can print 8.5x11. I bind the calendars I make for the family, too."