Читать книгу Henley's Formulas, Recipes and Processes (Applied Chemistry) - Various - Страница 131
Envelope Gum.
Оглавление—The gum used by the United States Government on postage stamps is probably one of the best that could be used not only for envelopes but for labels as well. It will stick to almost any surface. Its composition is said to be the following:
| Gum arabic | 1 part |
| Starch | 1 part |
| Sugar | 4 parts |
| Water, sufficient to give the desired consistency. |
The gum arabic is first dissolved in some water, the sugar added, then the starch, after which the mixture is boiled for a few minutes in order to dissolve the starch, after which it is thinned down to the desired consistency.
Cheaper envelope gums can be made by substituting dextrine for the gum arabic, glucose for the sugar, and adding boric acid to preserve and help stiffen it.
