In the 19th century, an art form known as lithophanes was all the rage in Western Europe. These thin engravings are usually made of translucent materials such as porcelain or wax. When illuminated, a glowing 3D image will appear that will change its characteristics in response to variations in the light source. Now researchers have revived this art form to create tactile graphics to illustrate scientific data glowing with high resolution. According to a recent paper published in the journal Science Advances, these lithophanes are accessible to sighted and visually impaired people, making them a universal visualization tool for scientific data.
“This research is an example of art making science more accessible and inclusive. Art saves science from itself,” said co-author Bryan Shaw, a biochemist at Baylor. “The data and images of science – for example, the beautiful images coming from the new Webb telescope – are inaccessible to people who are blind. However, we show that thin translucent tactile graphics, called lithophanes, can make all these images accessible to everyone , regardless of sight. As we like to say, ‘data for everyone’.”
The word “lithophane” is derived from the Greek litho (stone or rock) and phainein (to cause to appear), commonly translated as “light in stone.” The art form’s roots can date back to ancient China, as much as 1,000 years before the Tang Dynasty. (Historical sources describe paper-thin trays with hidden decorations.) But to date, no actual lithophanes are known to have existed in China before 1800.
Exactly who perfected the process of making lithophanes is still debated among historians. The common 19th century process involved etching a 3D design into a thin sheet of translucent wax or porcelain using traditional relief and intaglio techniques. More light would shine through the parts of the carving where the wax was thinnest.
These lithophanes were between a sixteenth of an inch to a quarter-inch thick. They were displayed as plaques, hung in windows or in front of shields with lighted candles behind them as a source of light. Lithophanes can also serve as night lights, fireplace screens, tea warmers or ornaments engraved with erotic images. American industrialist Samuel Colt filled his home in Hartford, Connecticut with more than 100 lithophanes and commissioned 111 lithophane versions of a photograph of himself to give to friends and associates.
The technique fell out of favor after the invention of photography, but the advent of 3D printing has revived interest. Today, lithophanes are typically made with plastic, 3D printed from any 2D image converted to a 3D topograph, according to Shaw and his coauthors, which they did using free online software. Four of those co-authors were blind since birth or childhood, but still successfully completed their Ph.Ds. But they are rare examples. Finding a way to create universal tactile science graphics that both blind and sighted individuals can use will remove a longstanding barrier that has kept many visually impaired people out of science.