Definition: Natural sepia ink is a powerful dye made from the ink of the cuttlefish. Sepia is a very dark brown, almost black in full strength. At even quite moderate dilutions, sepia ink is quite opaque, but more dilute washes are transparent, with red undertones. The manufacturing process makes sepia ink acidic, which can damage paper, and it is only moderately lightfast. Most modern pigment ranges replace sepia with modern dyes or pigments to create similar hues. The sepia effect in photography is not created using sepia ink but rather by bleaching of the print, or modern photographic techniques which duplicate the sepia toning effect.