If the sheets do not dry within a day, the blotting paper should be changed. Fragile sheets of paper should be handled by being placed on a plastic sheet. When dry, light pressing is needed to flatten the paper. It may be necessary to tone a piece of paper to match other papers. There are several simple techniques.
Coffee produces an opaque brownish hue.
Tea results in a limpid brown. Permanganate of potash gives a yellowish tone. The latter is very powerful and therefor the solution should be weak. All toning agents are put in the size. Be certain to sample the solution in order to have the correct resulting color of the paper.