I finally got around to making my 'free' Cath Kidston bag from the book Sew! All the fabric comes pre-cut.
Making the rouleau loop with this material was impossible! After googling for an hour I couldn't find anybody who managed it and ended up using ribbon or a knitted loop so I simply folded both sides into the middle and folded it in half (a little like bias binding) and it works just as well.
I also added a contrast lining to the bag to cover the raw edges which was surprisingly easy to do!