I bought this book when I was a student and over the years have been dipping into it, usually to seek specific information, but then one finds other fascinating bits which jump out at one. The book is a gold mine: it will tell you in depth about traditional pigments, their sources and how particular colours are made, how they react together, how to lay a suitable painting ground, gesso and the likes, how Vermeer, Rubens, Goya, Velasquez, Rembrandt, El Greco, and other great painters achieved their effects. It can generate ideas and be inspiring if you like experimenting and being in touch with those more organic materials. You have a more of a personal connection to them and it is like growing your own vegetables compared to buying imported ones. Once you thoroughly understand the workings and chemistry of a process you might think your way further experimentally and adapt it for your own purpose. You can then add to your arsenal of modern techniques.