Additional file 1 of Beneficial effect of gelatin on iron gall ink corrosion

Additional file 1: Figure S1. Sample preparation protocol by Focussed Ion beam (FIB). a inked fiber on a silicon wafer; b Pt deposit to protect the fiber and avoid sample charging; c trenches done with FIB (Ga ions beam) from each sides of the section; d thin cross-section of the sample fiber, surrounded by Pt (above) and Si wafer (below); d thin cross-sections on the A and C V-shape copper sample holder. Figure S2. STXM principle. Figure S3. Fiber I thin cross-section: a SEM observation, b and c STXM maps at the Fe L-edge. Map at 708 eV (after subtraction of map at 700 eV) represent FeII distributions; map at 709.8 eV (after subtraction of map at 708 eV) represents FeIII distributions. Arrow represents a region with a precipitate deposit at cross-section surface. Figure S4. Fiber G_I thin cross-section: a SEM observation, b and c STXM maps at the Fe L-edge. Map at 708 eV (after subtraction of map at 700 eV) represent FeII distributions; map at 709.8 eV (after subtraction of map at 708 eV) represents FeIII distributions. Figure S5. NEXASF spectra of three different regions of fiber G_I at the N-K edge (see Fig. 4). Figure S6. Fiber I_G thin cross-section: a SEM observation, b STXM map at N K-edge: 401 eV (subtracted by maps at 398 eV) representing gelatin distribution c and f STXM at the C K-edge at 288.3 eV and 286.7 eV (from which maps at 280 eV were subtracted), representing respectively gelatin and fiber major presence in bright. d and e STXM maps at the Fe L-edge. Map at 708 eV (after subtraction of map at 700 eV) represent FeII distributions; map at 709.8 eV (after subtraction of map at 708 eV) represents FeIII distributions. Table S1. STXM NEXAFS measurements conditions.