This is one of these ideas that when you hear about it you can’t believe it hasn’t been around for years. Touchable ink, developed by J. Walter Thomson in Bangkok is an ink-jet ink which sits on the paper creating, as it were, instant embossing. The Digital Reader has the story.
This sounds great, and if it can be used in a regular digital print engine (even one which has to be only slightly modified) one could easily see it making books for the blind available more cheaply than can currently be done by Braille printers. One could even imagine its being set up as a dedicated manufacturing line in a large print-on-demand facility so that books for the blind could finally be available on a one-off basis. If however it has to be done on something like a 3D printer, the economics could be problematic: at least we already have a large installed base of digital printers in the book manufacturing industry.
Obviously this has to be different from the thermographic printing which I have had on my business card for years. Wikipedia describes this older process: the second paragraph, Thermography as raised print process is the place to look. It all sounds a bit complicated, which is obviously a cost barrier. I wonder if it’s hard to control with small type detail: probably.