Braille
This page hosts information on adding Braille to 3D printed tactile graphics.
35-37 point font, with 37 point being preferred by most braille readers who have provided feedback.
| Dimension | Value |
|---|---|
| Character Height | 7.41mm-7.83mm |
| Character Width | 4.32mm-4.57mm |
| Center to Center | 3.09mm-3.26mm |
| Dot Diameter | 1.235mm-1.305mm |
| Dot Height (z-axis) | .2mm * |
| Center to center of corresponding dots in adjacent cells | 8.03mm-8.48mm |
- Standard braille dot height is 0.5 mm. On a 3d printer, this height is produced by 3 layers (passes) of filament producing something akin to a stack of pancakes. The stack has hard edges that snag the finger pad when reading. This slows reading and comprehension. Using 0.2 mm height requires only 1 layer, does not snag the finger pad. Testing with braille readers shows it is comfortable to read.
3D printing braille can be difficult to get right, especially when printing smaller sized braille consistent with BANA size standards. For that reason, we have explored combining the 3D printing method with more traditional methods of braille production. This is still in experimentation and we may find that it becomes obsolete once more universal settings for 3D printing braille and a 3D printable braille font is developed.
Braille labels are a great alternative to 3D printing braille. They are fast and easy. They do incur an additional cost but can be especially helpful if one has access to an embosser to make an associated key. They can be trimmed with scissors to size to omit printed information and tactile graphic makers do not need to be proficient in braille to use them.
A slate and stylus can add braille to a 3D print. It can even emboss on .2mm layer thin PLA as well as seen in the graphic below. The slate and stylus requires a user to know braille to use it. The slate will also leave holes where it clamps down on the graphic which is visually unappealing but does not affect tactile legibility. The method can be cumbersome as well as it usually requires multiple placements of the slate and proper alignment can be difficult to achieve.
A braille type writer or brailler can accept 3D printed .2mm layer thick tactile graphics. The paper does become curled after use in the braille writer but in initial trials the PLA has adhered to the card stock. The brailler typewriter can also emboss on .2mm layer thick PLA though the keys need to be pressed with force.