There is no method of absolutely fixing indian ink rubbed in water from the stick; alum or liquid ammonia is, however, commonly added for the purpose. Before waterproof ink was invented, it was customary to strain the sheet of drawing paper with glued edges on to the drawing-board, make the drawing with stick ink, wash it all over rapidly with a wet sponge, and then let it dry before colouring. The rapid washing-took off the surplus ink without smearing, and did not materially reduce the blackness of the lines. AVater-proof or fixed ink is by far the best thing to use for lines, and stick ink for washes and shading.