From dot-matrix to 3-D, printing technology has come a long way in 40 years. But all of these technologies have created hues by using dye inks, which can be taxing on the environment. Now a team reports inACS Nano the development of a colorless, non-toxic ink for use in inkjet printers. Instead of relying on dyes, the team exploits the nanostructure of this ink to create color on a page with inkjet printing.