For quantitative determination of lignin, we have invasive (gravimetric determination i. e. ASTM, TAPPI, SCAN) and non-invasive methods on our disposal. Invasive methods are not suitable for historical documents. On the other hand, several spectroscopic techniques are in use, based on IR and UV spectroscopy. The absorption of light of λ > 300 310 nm by pure cellulose is minimal and most UVspect...