A hectograph is very simply and easily made and by means of it many copies of writing can be obtained from a single original. Make a tray of either tin or pasteboard, a little larger than the sheet of paper you ordinarily use and about 1/2 in. deep. Soak 1 oz. of gelatine in cold water over night and in the morning pour off the water. Heat 6-1/2 oz. of glycerine to about 200 deg. F. on a water bath, and add the gelatine. This should give a clear glycerine solution of gelatine.
Making Copies with the Hectograph
Place the tray so that it is perfectly level and pour in the gelatinous composition until it is nearly level with the edge of the tray. Cover it so the cover does not touch the surface of the composition and let it stand six hours, when it will be ready for use.
Make the copy to be reproduced on ordinary paper with aniline ink; using a steel pen, and making the lines rather heavy so they have a greenish color in the light. A good ink may be made of methyl violet 2 parts, alcohol 2 parts, sugar 1 part, glycerine 4 parts, and water 24 parts. Dissolve the violet in the alcohol mixed with the glycerine; dissolve the sugar in the water and mix both solutions.
When the original copy of the writing is ready moisten the surface of the hectograph slightly with a sponge, lay the copy face down upon it and smooth down, being careful to exclude all air bubbles and not shifting the paper. Leave it nearly a minute and raise one corner and strip it from the pad, where will remain a reversed copy of the inscription.
Immediately lay a piece of writing paper of the right size on the pad, smooth it down and then remove as before. It will bear a perfect copy of the original. Repeat the operation until the number of copies desired is obtained or until the ink on the pad is exhausted. Fifty. or more copies can be obtained from a single original.
When through using the hectograph wash it off with a moist sponge, and it will be ready for future use. If the surface is impaired at any time it can be remelted in a water bath and poured into a tray as before, if it has not absorbed too much ink.