Tactile Test Prints

3 Pages swell paper with maths graphics and formulas on a black background.

The first few pages.

Not much to add to the previous posts, but we have a bunch of actual pages for the braille project ready, and we got some of them printed for testing.

Pages of a tactile maths book, chapter polynomial functions

Close up of the polynomials maths page.

It’s still hard to get the puffed up parts to show. I had to turn the contrast up a bit, but I hope it’s clear.

Some of the pages have been printed in all black on accident – which is the usual mode for tactile pages. While it was a bit annoying at first, it made us aware that we need to be very clear about communicating the intention of the red text, and add printing instructions accordingly.

Close up of a page of swell paper, showing graphs with several different textures

Viele Schraffuren.

Stage 2: Experiments

Now that I understand how microcapsule paper works, it’s time to get a bit nerdy with material science.

Most blind students in Austria attend regular schools, so they will have sighted people around them. This is why we decided to try and make the materials work better for this integrative approach by including the text in schwarzschrift (literally black print, I don’t think this term exists in English so I’ll stick to the German) too. Schwarzschrift here, for us, is red though. There’s technical reasons for that, but maybe I need to explain how swell paper works first.

Pages of swell paper with test lines in different line styles and red writing in different shades that has stayed flat in the swelling process

Testing different shades of red by applying different heat settings.

Close up of swell paper with black, 3D lines and flat red writing.

Now to find a colour that is the easiest to read for sighted people while not interfering with the tactile parts of the page.

The basic idea is simple: Microcapsule paper, or swell paper, reacts to heat. It is being printed on like regular paper, but after printing it is put through a machine (the fuser) that heats paper up using infrared light. When the infrared light hits the printed pigment, the paper underneath the pigment gets hot enough to swell up (It’s a bit like popcorn).

Since the swelling is caused by a combination of black pigment on the special paper and infrared light, changing parameters means it is possible to print content that won’t puff up when put through the fuser. Specifically, red ink absorbs less infrared light and heat and therefore doesn’t make the paper swell up.

So why is this a good idea? Braille has a very low density of information, so one page can fit much less text than it would with schwarzschrift. Space on a Braille page is precious, so we do not want to take up space with text that doesn’t need to be tactile. Additionally, having the schwarzschrift parts swell up would be confusing when reading the Braille and tactile graphics.

A Page of the Pythagoras chapter. It has labelled tactile triangles. The text is available both in Braille and in red for readers that cannot read braille. This is the first finished page from the short test chapter we are using to test the basic design.

If the schwarzschrift text does not swell up in the production process, it can just exist in the white space of the tactile page. Reliably being able to have content that swells and content that does not means we can make the most out of the limited space we have available while still providing all the information for different readers: It simply adds another layer of information that is imperceptible for those who don’t need it.

Nicht weinen? (Über verschütteter Milch)

Mein Schreibtisch steht vor einem Sonnenfenster das auf eine verkehrs-beruhigte Straße mit Supermarkt schaut. Menschen fahren andauernd mit vollgeräumten Einkaufswagen durch meine Straße. Faszinierend, was da alles unter Achzen und Knarren mit den „ausgeliehenen“ Supermarkteinkaufswagen durch die Gegend geschoben wird.

Öfter fallen die dann beim Transport auch um. Weil es in der Straße zwecks Verkehrsberuhigung zu viele Randsteine gibt um dort einfach so gemütlich entlangzufahren. Der Supermarkt da vor dem Fenster ist besser als Fernsehen.

How to read Braille

Pages of swell paper with different surface patters consisting of dots, lines and crosses

A number of pages with different surface patterns and intersections of lines and patterns

My new design project is interesting. It mostly consists of maths and programming, combined with social research. After that, finally, some layouting and typesetting – but the final product will not necessarily look pretty. That’s alright though, since it’s not made to be looked at: We are working on teaching materials for blind and visually impaired students. More specifically, a graphics catalogue to be used in high school maths education.

A page of swell paper with different styles of dashed lines.

How do dashed lines behave and feel? How much difference is needed so we can distinguish styles by touch?

close up of swell paper with different dashed line styles

It’s hard to get a good picture of the three dimensional quality of the paper.

And this is exactly why I love being a designer: Getting to make things that work, no matter how contradictory the requirements may seem initially.

A page of swell paper with different dot pattern surfaces

Here I am trying to come up with different patterns to replace what would usually be different colours. After creating a lot of “test squares” we had teachers and students test them at the school.

Pages of swell paper with different surface patterns

Pages of swell paper with different surface patterns

I’m really looking forward to working on this project. I have never used swell paper before I was approached with this project, but it’s an exciting material. It makes it possible to create tactile graphics with a standard printer and a special device to actually make the print tactile.

The first step is testing the properties of the material we are working with so I can get a feeling for it. We are closely working with both blind students and teachers to learn the basics about tactile graphics and typesetting in Braille, but also about the Braille system itself.

Close up of swell paper with different surface patterns and line styles

Intersections and Lines that go over what would traditionally be coloured fields are much harder to distinguish in tactile graphics.

Next up: learning how to actually read Braille.


Ist das nicht unglaublich? Vor 2 Wochen gabs meterhoch Schnee und gestern saß ich kurz vor Mitternacht ohne Pullover draußen, weil es gerade so warm ist.

Und manchmal staubt der Saharasand von allen Autowindschutzscheiben, einfach so.

Ist es nicht unglaublich, wie sehr Alles über die ganze Welt verteilt miteinander verwoben ist? Nur meistens ist es nicht ganz so offensichtlich wie Saharasand der auf Wiener Parkplätzen von den Autos rieselt.

Posted in Life 22.04.2018

occasional dyeing

Posted in DIY 01.04.2018

Robot Invasion

I randomly stumbled across another installation by David Černý while I was out exploring the end of the world one of Prague’s outer districts and looking for birthday cupcakes.


Here is a quick gif I made while soaking up all the sun I could get after 2 weeks of end-of-march-snow. It was a glorious, colourful late afternoon and after 2 hours everything went back to cold and rainy. But I got sun and birthday cupcakes, and even at the same time!