Above: the cover completed
Below: the instructions
After this the textblock, with pre-pierced holes, can be sewn to the cover. Sew around two threads at a time, and make sure that these pairs are alternated, so that the same two threads are not pulled together each time. It is important to keep the tension here. It is a bit of an awkward book to sew, but very charming once done with a nice easy opening. Voilà !
Original design can be found here: www.annegoy.be/crisscross/