I made a bunch of these for my kids. I used felt for the outer layer and cheap costume satin for the inner. Using costume satin for the inner was a problem, as you need 60 inch wide fabric for this pattern, at least in sizes 116 and above. I had to piece my inner. I honestly did not even read the directions, so I can't speak to how the pattern is constructed. However, I am glad that I used the pattern because I would not have made such a full cape had I been drafting it myself, and it really is nicer if it is full like this. I made the 116 cm for my son who is exactly 116 cm, and it was not as long as I would like. So I would definitely lengthen it if you have enough fabric.

Like cinnamama said, I don't think it is safe to have ties at the neck. I used TouchTape (like velcro) instead. For the neck band, I used a piece of felt that was 3" x 20" in length, folded in half to enclose the raw edges of the cape at the neck opening.