How rubbers must be. Rubbers characteristics. Erasers or Rubbers

• History of drawing
• Drawing materials

Rubber

Not the whole drawing process consists on " how to dirty the paper ". There are times when we need to eliminate graphite areas, to erase the pencil after inking , to reduce the intensity of the drawing, to create shades, reflections and textures. There are true artists that use the rubbers like an added drawing instrument.
The market offers a wide range of erasers. Diverse types for diverse drawing techniques.

Types of rubbers

Malleable rubber: It is a plastic material, similar to an non-oily plasticine. Due to their composition, it doesn't present a solid structure. Being malleable, it allows us to alter its form, to stretch it, to knead it and the most important thing: it does not become spoilt when rubbing it against paper.
It is ideal for soft graphite or for charcoal. It does not leave any particles so it doesn't damage the paper. It only picks up part from the graphite when entering in contact with the drawing.
It has the advantage of being able to access to very small areas. It was invented to clean the the typewriters dust . When its qualities were discovered, it also began to be used in drawing.

Caoutchouc rubber: It comes in bar forms (square, rectangular, rhombic, with rounded or pointed edges, ...). One can make a subclassification of different caoutchouc rubbers. On one hand those that literally fall to pieces when they enter in friction with the paper. Called breadcrumbs rubbers, they are ideal for soft lines. The soft pencil should always go accompanied by this rubber. Being so flimsy, it doesn't damage the surface of the paper which allows its abundant use with papers of quality without fear to damage them. Its main inconvenience: it leaves the whole work area dirty and it presents very short life. It is very convenient to clean the whole paper and its surroundings when using this rubber. There are many times when we ruin the drawing when drawing on a rubber crumb that hides behind the paper or when taking with us some piece from the paper. For those that are not very pleased with this kind of rubber, the hard plastic rubber exists. It is practically the same as the breadcrumb rubber although not so degradable. It has a stronger texture so, it does not break so easily . This avoids that waste of garbage on the table. When wearing away, it produces small compact ribbons which can be easily picked or cleaned. But it does not protect the paper so much as the first one does. Being harder, it scratches the paper more. This means that, with an excessive use, it can ruin the fibers of the paper. The tint rubber it is an example of evolution of this type of caoutchouc rubbers. Among their substance minuscule metal pieces exist that tear the most superficial layer in the paper taking the drawing with them They are thought to erase tint since it is not possible to be eliminated with any other rubber type. They have the inconvenience of severely damaging the areas of the paper that they erase

Rubber holder pencil : A sort of pencil that has substituted its interior for rechargeable rubber bars.

Erasing electric machines: In specialized stores they offer this product type. It is an electric device that sustains a rubber bar in rotation. It facilitates the task of erasing since it doesn't require the human effort of extending the rubber up and down.

Corrective liquid: It is served in small bottles, provided with little paintbrushes, or in markers. They contain a dense white paint that hides the dark color under their layers. Corrective liquid has an inconvenience: once dry, the covered surface can be easily stained if we work with graphite. If we keep this zone clean, we can see it doesn't become yellow.