1. Erasers with low contents of abrasive substances and with large contents of substances making the erasers material more elastic. They are intended for fast and qualitative deleting of graphite lines. The principle of deleting consists in sticking of graphite to eraser and in removing of graphite by friction of eraser on the surface at the same time. Owing to these properties of eraser its erasing surface is constantly replaced and updated. If the eraser is sorted out correctly to the paper and graphite so the working surface remains with minimal damages or no ones at all.

2. Erasers with the smaller contents of softening substances and with low contents of abrasive substances, such as pumice or sandpaper, and the bigger percentage of other substances and dyes. These erasers are for regular use.

3. Firm erasers with the high low of abrasive substances. As abrasives the sandpaper or pumice (the crushed volcanic glass) are used. They are able to remove the top layer of the paper by friction together with a line. At the same time the surface of the eraser is partially erased together with them. At deleting on the bad-quality paper they can rub it to holes.

4. Special erasers consisting of rubber only and a plenty of vegetable oil with no abrasive substances at all. During their manufacture vulcanization is rather small. As a result very sticky and easily deformed erasers appear. Owing to strong adhesiveness of the eraser the poorly keeping layer of working surface sticks to the eraser very well. This property is used at drawing by coal or dry chalk. Adhesion to the paper at these materials is weaker than to the eraser. The pasted trace remains on eraser, not leaving its surface and gradually spoils eraser.

As times go by rubber erasers become firmer. The process of hardening is accelerated if erasers are on open air or under direct sunbeams, therefore it is recommended to keep them over wrapped. If conditions of the storage are kept, erasers save their properties for many years.

Synthetic rubber erasers

Synthetic rubber erasers or plastic erasers as a rule have the decorative shapes, different combinations of colors and certainly any images.

These erasers are intended for the paper, the tracing-paper, the drawing film. They practically don’t cause the occurrence of the static electricity, what makes the adhesion of erasers waste to a working surface considerably smaller. Usually vinyl erasers leave wide long parties. It means that the smaller amount of movements is needed for removal of graphite traces from the work surface and the erasers waste are brushed away from the working surface easily. Unlike rubber erasers vinyl erasers don’t go bad in the course of time.

Some kinds of the vinyl erasers contain microcapsules with solvents. Such erasers are used for deleting of ink and multi-markers traces. The very small cells containing solvents inside of the eraser break at the deleting. Solvent provides fast clean deleting without the damage of the working surface.

Mechanical erasers

These erasers are used at mechanical deleting of lines and traces from the working surface. They contain the abrasive materials and scrapers. But it is necessary to remember that a part of the surface is deleted with lines.

Mechanical glass-fiber eraser has on the end a congestion of narrow fiber glasses which are located parallel inside of the bush that provides their rigidity. When fibers are used up, the moving mechanism submits a new part of fibers. The working part of fibers of this kind eraser should have short length. These erasers are right for deleting of any ink lines and even of rusty spots from the car. They are very abrasive and demand the cautious use.

The knife of correction is applied for erasure thick lines and traces, when the use of eraser takes a lot of time. The deleting consists in the erasure of the lines by a knife blade located of perpendicularly working surface. At the deleting it is necessary to be cautious because at strong pressing the working surface is damaged.