I get a lot of questions from people who are starting to do some bookbinding and I try to give easy answers; but, technique is something that is hard to describe in an email message. One question I get, is how to case in a textblock and keep the endpapers straight. First of all, practice many times. It's easier the hundredth time. I thought it might be helpful show a video, so here is a clip of me as I case in a text block. If this step is one that you struggle with, maybe you will see something helpful in my technique. No guarantees, though. Sometimes my endpapers are still crooked!