The technology of manufacturing special
Types of paper

Rainproof paper

Dissolve 500 g of snow-white soap in 0.5 liters of water; Then prepare a solution of 100 g of gum arabic and 300 g of carpentry glue for 0.5 liters of water; Preheat both mixtures, merge together and immerse the paper in it. When the latter is well moistened, it is removed and allowed to dry at room temperature. The paper thus treated becomes fully waterproof and can be used as wrapping, protecting objects from wetting with water.

There are other ways: immerse the paper in an aqueous solution of shellac with borax or take 1 part of the joinery glue also dissolve it in 10 parts of water, add a solution of 1 part of alum in 10 parts of water. The paper is immersed in this mishmash, but then it is dried.

In order to make the paper waterproof, we recommend impregnating it with an aqueous solution of liquid glue, technical gelatin or casein with 1% formalin.

Preparation of tracing paper

For the preparation of transparent copy paper, or tracing paper, wax in turpentine, impregnate this solution with thin writing paper also allow turpentine to evaporate, after which the paper becomes transparent and ready for use.

Paper can be given transparency also with the help of gasoline: they impose on the image from which they want to make a copy, thin writing paper and, after moistening a small piece of cotton wool with gasoline, carry them on paper. The moistened portion of the paper is made completely transparent and it is possible to paint on it not only with a pencil, but it looks like ink, but then with watercolors too: neither ink nor paint blur out. Gasoline quickly escapes, and the paper still retains its initial appearance. If the drawing is large, then the paper is cut in parts and the pattern is copied in parts; Gasoline disappears no sooner than the work is finished.

Preparation of copying papers

A blue paper, prepared as follows, is often used for copying. Take 10 weight elements of good French blue or Berlin azure, crush and pour it with 20 parts by weight of vegetable olive oil, to which 1 weight element of glycerin is added. This mixture is left for a week in a dry, warm place at a temperature of 40-50'C also stir from time to time, but then, when the French blue is impregnated with oil, it is well rubbed. When the blue paint is thus completely ready, 0.5 wt.% Yellow wax is slowly blown out and gradually added to it 1.5 parts by weight of petroleum alcohol, known on the market as naphtha, later 3 parts of the powder are added to this last mixture With oil of French blue; Heat all up to 30-35 ° C and also thoroughly grind until a completely uniform consistency mass is obtained. This mass with a wide, soft brush of bristles is applied to paper, so-called silk, and then, with a broad brush or flute, level the layer so that it is evenly distributed, after which the paper is dried and then it is completely usable.

Filter paper

To filter paper not so quickly broke, which often happens when filtering impressive amounts of liquid, a simple tool is recommended, which, significantly increasing the strength of filter paper, does not in the least reduce its filtering ability. The means is that the paper is immersed for a few seconds in nitric acid with a specific gravity of 1.42 and then immediately thoroughly washed in water. The paper prepared in this way can also be washed as if it were a canvas; It is made so strong that a strip of ordinary filter paper with a width of 5-6 cm can withstand a weight of 1.5 kg, while a similar band that has not been subjected to nitric acid in any way, is torn from the gravity of 150 g, ie . Is ten times less durable.

Filter suede

Filter paper, as it is known, owns a flaw, in that through it the liquids are filtered relatively slowly, in particular more or less viscous and viscous consistency. This drawback is especially noticeable at what time a significant number of these liquids are filtered. In these cases, the filter paper can be successfully replaced with suede. A piece of suede is soaked in a weak solution of soda to remove the fats contained in it and then thoroughly rinsed in cold water. The suede prepared in this way is used as a filter paper. Through it is very clean, and together with that, not only all sorts of tinctures are filtered quickly, but also very thick syrups, but it seems like thick, mucous plant juices. The speed of this process can be discussed already by the fact that a liter of the most viscous syrup is filtered in 15 minutes. Another important plus of filter suede is that it can serve very long; It is only necessary to wash it thoroughly every time after use.

How to recover faded ink on parchment

To do this, it is enough that the room on the parchment, from which the ink has come off, is covered with a brush of a layer of ammonium sulphide. This tool has been tested a long time ago and is also successfully practiced, as appropriate, by the Oxford Library.

Washable working drawings

It has been known for a long time that the drawings that are in the workshops are made in time with such dirty ones that are also unclear, that the numbers indicated on them and the dimensions can often not be disassembled. In order to protect the drawings made in carcasses or in a pencil from contamination, we advise putting them on a glass or on a plate also covering them with a collodion, to which 20% of stearin is added. After 15 minutes, it dries up also alienates a pure white color with matte gloss. Thus, the drawing is covered with a protective layer, which can be washed with clean water, without fear of washing off the figures as well.