Thought it would be useful to point out that the two books written by Angel Gair - Tonal Values and Tonal Painting are the same book. The only difference is that Tonal Values appears to be a newer version of Tonal Painting, with the words 'tone' in the book replaced with 'value'. I have bought this book, but am yet to start reading this. This information might be useful for anyone thinking of buying either book.