We present a fundamental development step of a new technique to read and digitize ancient handwritten documents. Chemical analysis by x-ray fluorescence and x-ray tomography enabled us to decipher words and drawings from inside a closed, 200-pages 18. th century handwritten book. The ink chemistry is essential: tomographic reading is feasible thanks to the iron present in ancient inks (iron gall) over one millennium-whereas carbon or organic inks do not provide sufficient x-ray contrast. The results presented are a key progress towards the ultimate goal of the technique: non-invasive reading of fragile and/or unopenable documents.