Visitors to last year’s World Expo in Shanghai might have noticed that the outer walls of the Italian pavilion were kind of... unusual. Although they felt solid, and looked like concrete when viewed from an angle, light was able to pass through them. How was it possible? They were made from what the Italcementi Group refers to as “transparent cement,” and has trademarked as i.light. It’s definitely a unique substance, as it blurs the line between wall and window.

The material was created specifically for the pavilion, as architect Giampaolo Imbrighi wanted a building with transparent walls. While the exact fabrication method hasn’t been fully divulged, Italcementi states that it involves “an innovative cement/admixtures mix design.” That mixture reportedly bonds well with thermoplastic polymer resin, which is inserted into a matrix of 2-3 mm holes running through the width of each panel.

There are approximately 50 holes in each 500 x 1,000 x 50 mm (19.7 x 39 x 2 inch) panel, resulting in an overall transparency of about 20 percent – the pavilion also included semi-transparent panels, which had a transparency of 10 percent created by “modulating the insertion of the resins.”

Past attempts at similar materials have included placing fiber optic cables through a concrete mixture, although the Italcementi researchers claim that their product is much less expensive to produce, and allows light to enter from a greater number of angles.

Although i.light has yet to be made available for commercial use, it has already been suggested that buildings made with the material could save electricity that would otherwise be required for daytime lighting.

Via Popular Science and