I was going to use two different sewing methods, but the defeats the purpose of sewing two books to work out problems so you end up with one well executed book.
Once the textblock and endpapers are folded and flattened, its time to make the sewing stations. I cut some bias tape (1-2cm) to sew the signatures on and use them for a guide to saw the station holes. I also saw about 1cm from each end for the kettle stitch. It is important to make sure that when you saw the signature stations that the textblock is lined up and square, if at this stage you are not meticulous then you'll be headed for heartache down the road. You need to make sure that the sawing only cuts to the inside folded paper on the signature, too far thru that and the textblock will not be tight, it'll twist & warp in the final product. Errors now are harder to fix down the road. I prefer to use linen tape, but cotton will do.
I then prepare the thread for sewing. Traditionally linen is used because of its durability, so I have a large spool and that is what I use. Its brown, and I also have some very fine white linen thread - better for large textbloxks. This is a thicker thread, but the textblock is small. I cut about arms length, any more and the thread gets in the way and a little cumbersome to use. Also, there is some wear on thread and sometimes twisting if the station holes are tight. I wax the thread with bees wax instead of regular wax because it feels cool. I am not aware of a good reason other then that. This is done so that the thread is easier to handle (doesn't make knots by itself) because it is stiffer as well the wax bites into the paper and holds so that the sewing is uniform and tight. Loose sewing makes for naughty textblocks. One error early in the process means that you have to compensate later on. And that leads to bad bookbinding. We want to play nice.
Once the textblock is sewn, I will strengthen the spine by adding paper & glue. Once this is done I will then add the mull. I am using cotton but traditionally linen is used that is loosly bound so that the glue will penetrate through to hold it securly. This is more important for machine binding as opposed to hand binding. Let this dry overnight. Whenever pasting, it is best to let it dry before moving on to the next stage, of course if you are in a hurry, plod on.August 26, 2009.