Swelling paper
Swell (also Schwellkopie and source of paper ) refers to a special paper for the simple and inexpensive production of tactile graphics mostly for the blind . A thermoplastic PVC layer is located on a carrier paper .
use
Swell paper can be painted or printed with standard printers. After painting or printing, the paper is briefly illuminated in a special device, whereby the blackened areas heat up. They swell permanently and can then be felt. The strength of the expression can be controlled to a certain extent by blackening, temperature and duration of heating. This corresponds to setting the contrast on printers. This process creates a tactile graphic within a few seconds. Here, let graphics , sketches, diagrams and maps make accessible to the blind.
Another possibility of use is writing or drawing with a heat emitting pen, whereby the further processing step of lighting is omitted.
However, the possibilities are not comparable with the visual representation. The haptic graphic corresponds most closely to a pure black and white image without gray values. Only very simple graphics can be translated 1: 1 so that the representation can also be understood by the blind. Alternatively, the scale of the representation must be increased significantly. This is due, on the one hand, to the different functioning of the sense of sight and touch, as well as the different mental representations of the environment in sighted, later blind and birth-blind people.
This process is therefore not always suitable for everyday use because of the effort involved in producing or finding suitable graphics, high material costs (around 50 cents per A4 page) and the time it takes to create each page. To this day, its use has been limited to isolated applications, for example for the reproduction of teaching material for blind pupils and students. In contrast to the duplication of tactile maps by manually producing a template for deep drawing , the process is simple and very inexpensive.
Since the swell paper can be printed in color, it can also be used to generate graphics that can be understood by blind and non-blind people alike, thus enabling communication between the blind and the sighted or supporting the perception of severely visually impaired people with strong contrasts.
Some artists have also discovered swell paper as a medium for themselves.
Swell paper and the swell copier (fuser) required to swell it are available from auxiliary supplies.