Abstract <p>The Raman spectra of ink from two 15th-century manuscripts and replicated inks simulating formulations common in medieval Russian written culture are analyzed. Two main sources of tannin, gall nuts and alder bark, are used in the preparation of the replicated inks. The sets of bands in the Raman spectra of ink from manuscript KB 295/552 on three pages are found to be similar to those of model inks made from gall-nut tannins. Based on the presence of a band at 980 cm^–1 in the spectra of ink from manuscript KB 295/552 on three pages, an assumption is made about the use of alum or iron sulfate in the formulation of the ink. Based on the observed bands in the Raman spectra of the ink in manuscript FI-792, it is concluded that the ink on page 12 was made using gall-nut tannins, while the ink on pages 41 and 157 was made using a bark decoction. In addition, due to deterioration of the original iron-gall ink, many letters on various pages were retraced with carbon-black-based ink.</p>