How to Preserve Pencil Sketches.
The pencil drawings of mechanical draughtsmen and engineers may be rendered ineffaceable by the following process:—Slightly warm a sheet of ordinary drawing paper, then place it carefully on the surface of a solution of white resin in alcohol, leaving it there long enough to become thoroughly moistened. Afterward dry it in a current of warm air. Paper prepared in this way has a very smooth surface. In order to fix the drawing, the paper is to be warmed for a few moments. This process may prove useful for the preservation of plans or designs when the want of time or any other cause will not allow the draughtsman reproducing them in ink. A simpler method than the above, however, is to brush over the back of the paper containing the charcoal or pencil sketch with a weak solution of white shellac in alcohol.