1. Introduction: tree fractionation from old postulates to a new paradigmC. Hagiopol2. Trees: a sustainable source of lignin and tanninC. Hagiopol3. The tree fractionation: the extraction of natural polyphenolsC. Hagiopol4. Wood tannins: structure, production, and analysisK. Cheng5. Industrial scale lignin recovery from pulping liquorsK. Cheng6. Lignin characterization: structure, size, and stabilityK. Cheng7. Capitalizing on lignin and tannin value: their chemical reactivity and their potentialC. Hagiopol8. Natural polyphenols applicationsC. Hagiopol9. Wood reconstructionC. Hagiopol