This is a good book for seeing what effective use of masking can do for a painting. Mr. Roycraft's use of masking is an integral (if not THE prime) technique for creating the numerous paintings demonstrated in this book. The other technique he uses is pouring the watercolors onto the surface rather than painting most of it with a brush.
This is not a painting method for anyone not willing or able to know precisely all the places to mask. The sparkling waves of an ocean in one of his paintings must have taken quite some time to mask and most likely needed a detailed pencil sketch beforehand. While the pouring is imprecise the masking is not.
The book has 1 chapter that gives a step-by-step demonstration of his pouring method. One can tell from some paintings produced that this can be a time-consuming method of producing watercolor paintings if the subject matter is intricate or detailed although the results are breathtaking.
I would like to see more demonstrations from Mr. Roycraft and perhaps more details about the masking as part of the process. Statements such as "I masked only the light areas before beginning the painting. This is negative painting in reverse and makes a beautiful abstract pattern." show the thought that guides the final results.
Most of the book shows paintings in a semi-finished state with the final result and some comments on the process and thoughts in creating it. I liked this book very much and would recommend it to any watermedia painter because it helps thinking in terms of positive and negative shapes and light. It also introduces a unique way of painting with watercolors which I suspect would work with fluid acrylics as well.