The drawing, ink on Japanese paper, resulted damaged with serious tide lines because of flooding. Other problems not associated with the flood were foxing, tape and tape stains and planar distortion.
Even if the tide line caused by the flooding showed that the water had reached the ink of the drawing, a careful observation under magnification as well as some spot testing indicated that the ink was completely insoluble in water. The treatment consisted in water immersion associated with light bleaching. This treatment resulted very effective not only removing the tide line, but also the foxing and the tape stains.