Fixing drawings

A drawing made with pencil, charcoal or chalk is easily obliterated and soiled, because it is held to the paper not by a binder, but by purely physical laws: tiny particles of coloring material are rubbed into the pores of the paper and held by the laws of mutual attraction of molecules. Therefore, drawing requires fixation, which more or less affects its tone.
The more firmly a drawing is fixed, the greater the changes in its tone.
Spirit fixatives darken the tone of the drawing more.
A pastel fixed with a fixative turns into a tempera.
Water-based fixatives change the tone of the drawing less, but it is necessary to stick the paper on a board or cardboard before fixation to prevent the paper from curling from moisture.

Water-based fixatives

Milk: It is largely a natural solution of casein. It has adhesive strength.
Use skimmed and diluted milk for fixation.
Milk is best for fixing graphite drawings.
Gelatin: 2% gelatin solution is taken for fixation. To it, add 10 ÷ 30% pure wine spirit or denatured alcohol.
Gelatin is suitable for fixing carbon drawings.
Before drawing, it is good to cover the paper with gelatin solution. Drawing should be done only after it dries.
After drawing, hold the drawing over steam - the gelatin will dissolve and fix the charcoal.

Water fixatives are sprayed with a sprayer. Spray very finely and be careful not to form drops.
It is best to fix the drawing gradually over a few days (after drying).

Spirit fixatives

These fixatives, due to their ability to be finer when sprayed, are easier to use, but darken the tone of the drawing and the paper itself.
The most popular fixative is made of white shellac dissolved in spirit (1 : 10 or 20).
It is best suited for charcoal drawings. It is not suitable for pastels and chalk.
You can also use gasoline fixatives (with such resins that dissolve in gasoline).
For pastels, a solution of cellulose in amyl-acetic ether is good, as it oxidizes faster than it penetrates into the paper and therefore does not darken the tone so much.