I finally finished this! The leather got here quickly but it took a lot of work to get the cover made. But I'm happy with the finished result, considering it was the first time I'd tried making a leather cover and only the second booklet I've ever made.
The leather was supposed to be green but no matter what light I look at it in, it looks brown to me. I don't mind; it's still just what I needed. It's thick leather but not stiff. I ordered it from TheLeatherGuyMN on etsy and got it within days. I ordered two pieces, so I had to sew them together.
First I trimmed the top of the pieces to just a little larger than the cardboard cover already in place. Then I sewed the two pieces together using the same technique I used for my lawnmower handlebar grips that I made this summer.
Once that was done I measured the piece again with the sewn edge over the spine of the booklet. I wanted the cover to be snug but not so tight that it would stretch. I trimmed the ends so that they would come right up to the inside edge of the first and last pages. Here's a picture of how I arranged the cover, before sewing.
After I was sure I had everything cut to just the right size, I glued the inside front and back flaps to the cardboard. I did not glue anywhere else, just here to keep the leather in place while I worked.
After that I had to sew the top and bottom edges in place. That's what took so very long. First I had to punch holes with the awl through both thicknesses of leather (and sometimes the cardboard), then I had to sew carefully to make sure the stitches were taut but not so tight they might pull through the leather.
I sewed from the edge of the cover to the spine, then knotted the threads from both sides and cut them short. Unfortunately, I cut them too short, forgetting that the upholstery thread I used is tough but thick so tends to untie itself if given half a chance (that's a problem with one of my lawnmower grips too; I need to repair it already). To keep from having to resew both sides, I cut a tiny piece of vellum paper (not real vellum, just the thick but transparent paper they sell to scrapbookers in craft shops) and glued it down over the thread ends to hold them in place. I then did the same thing to the other side even though the knot held, just in case.
Once it was done, it looked good--but there was a problem. I accidentally tore the paper edging the spine a bit, and that worried me that eventually the page might tear through. In the photo above you can see how flimsy that blue piece of paper is and it is pretty much the only thing holding the pages in place (there's a strip of cheesecloth too, but it's not that strong). Major oversight, plus that signature of the booklet wasn't as tight as it should be so it needed stabilizing anyway.
I wish I had realized this before I had glued and sewn the cover in place. It would have been easy to put a strip of vellum or something down before I'd made the cover. But it was too late so I did the only thing I could really do at that point without starting over: I cut more vellum (it's fairly tough paper, and I also had some on hand already) and glued it in place. I used as little glue as I could because I knew it would look bad and I also didn't want to wrinkle the pages.
I put a strip in front and one in back, then let them dry overnight while weighted. The vellum was almost invisible on the paper, and is prettily patterned anyway, but the vellum glued to the leather just looked horrible. To make the best of a bad situation, I drew all over those sections, front and back. At least now anyone looking at it will be too busy thinking, "What is that supposed to be, an octopus?" to notice anything else.
But despite the hiccups I'm happy with the result. It's handsome, sturdy, and I made the whole thing. I left room to add photos, and I already have some to add.
