About a year and a half ago, I made my younger sister a cover for her Bible. It is now fairly faded and beat up, and she wanted me to make her a new one. I made her get home dec fabric instead of calico this time.
So this time, I wanted it to be a bit bigger so I could topstitch around the edges, because that always makes things look sharp. I had the old Bible cover to work from, and you'd think that I would have been able to add the right amount when I was cutting it out. I thought I had it figured out perfectly. WELL, there was way too much left for the... topstitching area. (Don't know what to call it.)
I couldn't get a good photo of it before she took it.
I ended up making a double row of top stitching around the edges, which looks pretty good, but I still wouldn't have made it so big on purpose.
I have made three of these "binding bookmarks." I don't know what to call them. They slide into the space between the binding of a book and the cover. Two of them have gone into Bibles that already had issues with failing/faulty binding. The other went into a book with good binding that I don't use all that often. I haven't noticed that the bindings of those books have been adversely effected by having this very thin bookmark. But they might have. I don't know. That's my disclaimer.
Anyway, I make them with a long scrap narrower than the book so it can slip in the gap. Fold your long, skinny scrap in half. Arrange the ribbons so that they are not twisted or overlapping, and stitch across with smaller stitches than you usually use. My machine is automatically set to a stitch length of 2.5-somethings, and I turned it down to 1.6-somethings. (Are they... millimeters? Picas? I don't know.)
These are 1/8" satin ribbons, probably the best for bookmarks.
Stitch around the outside so your scrap will stay flat in the book. Resist the urge to finish the edges, unless you want to snip around them with pinking sheers. Any other finish will add unnecessary bulk that you don't want stuck behind the binding of your book.
This would have been better if I had measured it, used a wider scrap and spaced the ribbons out. Whatever.