Tactile diagrams are visual images modified for use by persons who are blind or visually impaired. Braille labels replace print labels. Lines, textures, spacing, etc., are adjusted for tactile readers.
The Disability Resource Center uses computer illustration software as the main tool in converting diagrams into tactile format. Most of the work is completed by manually re-drawing the diagram on a computer workstation. Currently, Macromedia FreeHand is the software used by the Disability Resource Center to draw the electronic version of the diagrams. Sometimes parts of the diagrams can be scanned and traced using FreeHand. This increases the speed of production and the scientific accuracy of the diagrams. Illustrators make every effort to preserve scientific integrity while rendering illustrations suitable for tactile readers.
As the text documents are processed, individual diagrams are entered into our tracking system as documents. They are also given unique ID numbers and are assigned due dates. Like transcribers, the tactile illustrators complete various tasks for the illustrations according to their due dates.
Using Thermal Imaging Paper
The Disability Resource Center uses thermal imaging paper, a coated paper that produces raised images when heated. When the electronic version of a tactile diagram is completed, it must be printed out on a normal computer printer, photocopied onto the thermal image paper, and run through a tactile imaging machine to raise the black ink on the paper. This process at the Disability Resource Center is commonly referred to as "toasting".
Many agencies are adopting a system of tactile diagram production similar to that used at the Disability Resource Center. Due to the young age of the technology, it is often difficult for new users to obtain a consistent, high quality product. Over the years, the Disability Resource Center staff have developed a standard procedure that helps guarantee the best results for toasting diagrams. Here are some strategies we've developed to maximize the quality of our diagrams:
First, when photocopying the diagrams onto capsule paper, best results typically come from using a bypass feed tray found on the side of a copier. The tactile paper must go through the copier horizontally so the paper is in the copier the shortest amount of time to prevent overheating in the machine and sticking to the rollers.
Second, store any unused capsule paper in sealed plastic bags containing desiccant. Capsule paper can absorb humidity, which can deteriorate its quality.
Third, before toasting, warm up the "toaster" by passing a blank sheet of capsule paper through it five to six times to ensure that the rollers are evenly heated.
Fourth, check toasted diagrams for quality throughout the entire process. Are the braille dots raised? Are the diagrams over-toasted? Over-toasting results in solid black areas being severely cracked or lines breaking off easily.
A complete description of Disability Resource Center drawing techniques is available in the TAEVIS Diagram Manual. A free copy of the manual is available here: