There are probably hundreds of books on origami around, but so many of them are aimed at beginners and are effectively interchangeable. Most have the obligatory traditional crane, frog and iris - some aimed at children simplify even these. Once you winnow these out, the choices become slimmer. This one is excellent, assuming you have mastered the basic skills and want new frontiers, but would not yet consider yourself a master. The four models on the cover give a good representation of what you will find there, some of the "simple" models (Lean-to, canoe) are more complex than the end product indicates, and the more complex will stretch your skills without driving you to insanity! My only complaint is that I'd like more models!