Yadong Yin
Despite the rise of electronic media, we still rely heavily on paper. Concerns about excess paper consumption have inspired practices that reduce material waste, such as the use of electronic textbooks and paperless offices. Yet we continue to use a tremendous amount of the material. The U.S. consumes about 69 million tons of paper and paperboard annually, according to the Environmental Protection Agency. In 2012, TheEconomistreported that the average American goes through the equivalent of nearly six, 40-foot-tall trees each year.

Seeking to reduce our consumption of the product, researchers at the University of California, Riverside (UCR), developed an alternative: reusable paper. The material employs commercial, color-changing redox dyes in blue, red, and green colors that are applied to a substrate such as plastic film or glass. To write with the dye, the inverse image of the information intended to be conveyed is photo-bleached onto the substrate, causing the text to appear in the colored hues. With the addition of heat, the dye can be brought back to its original, wordless state up to 20 times, erasing the writing in a process that takes about 10 minutes. (Watch a video of the process.)

"This re-writable paper does not require additional inks for printing, making it both economically and environmentally viable," Yadong Yin, a chemistry professor at UCR and the research team's lead, told Materials Today. "It represents an attractive alternative to regular paper in meeting the increasing global needs for sustainability and environmental conservation."

UCR's development presents a different user experience than that of conventional paper, with three bold color options and a transparent background. The process requires the use of manual photo-masking, so the researchers are developing a custom laser printer. Once deployed commercially, the combination of ink and substrate will encourage new resource-management tactics—such as returning used product to a central printing station and tracking the number of "lives" each unit has left before it, too, must be recycled.

Blaine Brownell, AIA, is a regularly featured columnist whose stories appear on this website each week. His views and conclusions are not necessarily those of ARCHITECT magazine nor of the American Institute of Architects.