What is a nag, artists know well. Like a piece of dough, it easily removes dirt from paper, without leaving nasty spools like regular erasers. From it you can pinch off the pieces and roll into a cone. Each time a nag touches a pattern, traces of graphite remain on it. In order not to transfer them back to work, they periodically crumple in their hands, like plasticine.
Previously, the crumb of white bread performed its function. O'Henry also wrote about this in the story Stale Rolls. A man in well-worn but neat clothes came to the owner of the bakery and bought stale bread. She decided to help the poor man, who did not have enough money for fresh pastries, and put butter in bread rolls. The furious architect ran to the landlady, called her, shaking her fists, - it turned out that he was erasing pencil lines with stale bread and this time ruined the whole drawing.
When O'Henry wrote his story, there was already a rubber band that was not loved because it became very tough over time. Until the mid 60-ies of the twentieth century, draftsmen used bread crumb.
Nag history
What is eraser, the world learned in 1770 from the English scientist Joseph Priestley. He left a diary entry about a great way to erase pencil inscriptions. This happened on April 15, and the remedy was the dried juice of a hevea tree, which the Indians called rubber. Priestley gave him the name rubber. Now is the day of eraser.
In 1839, vulcanization of rubber was discovered, which gave strength to this stationery. In the middle of the last century, synthetic rubber was invented, then they began to make rubber bands from PVC, vinyl and plastic.
Koh-i-Noor invented the gum by making it from polyisobutylene (a rubber-like product) with the addition of calcium carbonate and titanium oxide. The composition includes soot and pumice. The gag should be stored in the plastic box in which it is sold. If left open, it will be covered with a layer of dust. In this case, a thin dust layer is carefully cut. It is useless to wash it; on Gum Day it is customary to buy a new one.
Soft rubber that does not need to be soaked in gasoline
The heroine of the film “The Most Charming and Attractive” served in the design department of the research institute and possessed the envy of colleagues - a soft rubber band. In Soviet times, high-quality rubber was in short supply, so a regular school eraser was soaked in kerosene. For several days, the rubber did not dissolve, but swelled, became porous. It was wiped, dried and boiled, after which it was easy to remove traces of graphite with such an eraser.
The eraser used by the draftsmen now is released by the famous Czech company Koh-i-Noor, and it does an excellent job. From a smooth Whatman paper, he will remove the trace from the stylus without damaging the structure of the paper. They can erase pencil lines when the drawing is already circled with ink. It will not dim its brightness, like some tougher erasers.
Specially created by manufacturers for working with soft black lead pencils, the nag found application in pastel technique, coal, for sketching sauces and colored pencils. That's what a nag for an artist is.
The tool for creating chiaroscuro
The unique ability of a plastic gum to remove graphite with a simple touch led to a special technique for creating chiaroscuro. Graphite is applied to the paper (by hatching or brushing using graphite powder). Then, clutching a nag, lighten part of the picture to the extent that the artist needs.
Having plucked off a small piece, you can carefully form the desired shape from it to create a highlight. With a nag you can transmit semitones in pastel works and coal graphics.
How to use a nag shown in the video.
Conclusion
There is a short feature film "Nag" about how a girl entered the architectural institute. By the expression on the face of the teacher, from whom she asked for a spare nag, it becomes clear that this is a very important tool of the artist. In the film, the nag is not shown close-up, and the viewer may not understand what it is.
But now you know what a nag is. This is a simulated drawing eraser. The next time you visit the stationery store, pay attention to the plastic boxes with multi-colored fangs. Maybe one of them is waiting for you.