It is allowed to remain for a minute or less and is then raised by one corner and stripped from the gelatine surface. It will have left the reversed copy of its inscription perfectly reproduced upon the tablet.
At once a piece of ordinary writing paper of the desired size and quality is laid upon the tablet, smoothed down, and stripped off, when it will be found to have taken with it a complete copy of the inscription or writing. This is repeated over and over again with another sheet of paper, until the ink on the pad is exhausted. Fifty or more good copies can be thus obtained.
The Hektograph.
As soon as the work is completed the remains of the ink should be washed off with a moist sponge and the tablet, after drying a little, will be ready for a second operation.
Some practice is required to ascertain the proper strength of the writing and degree of wetness of the surface. When the gelatine surface becomes impaired it can be remelted in a water bath if it is not too dark from absorption of ink.
French Ministry of Public Work Formula.—Glue 100 parts, glycerine 500 parts, finally powdered kaolin or barium sulphate 25 parts, water 375 parts. Use a little hydrochloric acid in the water for washing off the pad after use.
Hektograph Sheets.—Four parts of glue are soaked in five parts of water and three parts of ammonia until soft. It is then heated and there is added to it three parts of sugar and eight parts of glycerine. The mixture is applied to blotting paper. This is saturated with it, and successive coats added until a smooth surface is produced on one side. This is the side for reproduction. It is used like the regular tablet except that it is claimed that sponging off the writing is not necessary. Owing to the capillary action developed by the blotting paper it is supposed to be self-cleaning by standing.