Eastlake is a true scholar who in 1847 published a massive exploration of all available manuscripts from ancient languages through the painters of his time. He synthesized this with is own practice of the time into around 1000 pages in the combined two volumes. Eastlake was president of the Royal Society and director of the British Museum -- something of a modern conservator, artist, and academician all in one.Expect to find explorations of a term like "sandarac" going on for an entire chapter. He quotes directly from numerous sources, translating from their original Greek, Roman, and other ancient language through medieval and renaissance sources and into the latest discoveries of his own era. He is searching for the holy grail{ the first mastery of oil painting as practiced by the Van Eyck brothers between 1418 and about 1455. Yes, he is fluent in Ancient Greek, Latin, and the various dialects and variations of all modern European languages. Yes, handwritten 15th century Venetian notes filled with eccentric abbreviations are not a problem for him. This is old school research, but I expect Eastlake was always an outlier. This becomes clearer as you follow him through several millennia as he finds the earliest manuscripts from 1200 BC and follows all the way through dozens of sources to establish a timeline in usage and discoveries of resins in varnish. It's safe to say, not many travelers who have walked these passages are alive today.On the down side, not everything is in English. He assumes his readers are the very literate painters of his era, meaning we can speak French, Italian, German and Latin at the least. You will need to look up some English words of Latin origin he assumes we know. I keep an index card glossary as a bookmark. I hear you thinking, "Oh, I'll know those terms." I'm laughing. How about Lixivinium and its verb form lixiviate? So, the book is not for everyone, but generally he translates most into English except for the footnotes which return to original sources most of the time. Sometimes the footnotes cover most of the page.The first volume covers any possible medium, pigment, varnish, technology from coating the inside of Phoenician urns with resin before filling them with oil up through modern varnishes used on tempera paintings. Schools, workshops, periods, and individual artist will be discussed along the way. While the 15th century is his idea of the modern era, he continues through the early 18th century. You'll learn about how the resin based oil varnishes on tempera paintings gradually crumbled off over the centuries, leaving the tempera surface unharmed. The transition to oil painting is a many hundred page discussion including a long section on ways to make tempera dry slower as they gradually move towards the era of the Van Eyck brothers. Encaustics on Egyptian panels through wax coverings on fresco applied hot and polished lead into ways waxes were mixed into some egg tempera paintings to slow drying and then allow polishing.If you were told Vasari was a credible source then you may be surprised to find an entire chapter dedicated to fact checking his account. He'll give you another half dozen sources to compare as he examines the credibility of what Vasari heard, who he heard it from, and where he likely heard it.He has a purpose: He wants to know how the painters of the past created specific effects and were able to accomplish things we might find quite challenging today. He wants to know exactly how it is done, and you can learn how to do it within a wide field of possible variations at different times. He doesn't assume anything is true just because he found it written in some 13th century manuscript. He compares it to a lineage of sources going back to the most ancient records and discerns where and when terminology changed. Sandarac can refer to a resin in oil varnish or to pigments that have the general color of the aged sandarac resin used in oil varnishes. Sandarac may refer to amber and copal resins in Germany or to a resin of a juniper species from Northern Africa in the Mediterranean workshops. All or none of the above may be relevant depending on where and when the manuscript was written.It's hard to imagine someone today who would have access to and be able to translate so many hand written manuscripts. Have you ever looked at even 18th century Venetian handwriting? The abbreviations can be unexpected, just as if we were reading Chaucer in his original manuscript. So, Eastlake was probably the perfect person at the perfect time: he was educated to speak all the languages of his field and he painted at a time when older painters still were preparing pigments, paints, mediums and varnishes themselves. But he was the last generation to be able to do that as paint merchants were taking over these tasks for artist and providing the ready made materials much as we find today. A lot was lost between the beginning and end of the nineteenth century. As for his ability to read and write in formal and colloquial versions from a dozen languages and dialects over a few millennium, well, that alone would make him unique today.So the point of all this is synthesis: he can put it all together. Towards the end of the book he moves into studio practice and art instruction. For most of the book he is sharing the sum total of knowledge about painting from ancient civilizations through the precursors of impressionism.For a contemporary approach to all this check out Tad Spurgeon's Living Craft and the many processes and materials you can make from Eastlake's research. I'd known about Eastlake's book most of my life, but it wasn't until reading Spurgeon's work that I got myself a copy of Eastlake to read. Spurgeon's understanding is that most of the texts written after Eastlake are unreliable at best. After a few months exploring Eastlake I definitely agree. I've been interested in mediums and pigments all my life, but am just now learning things I would have loved to have known long ago.