The Xerox ColorQube 9200 series of solid printer ink is a first in computing. Instead of liquid ink, these inks are made in hard cubes like crayons, and they melt down when it's time to print.
The technology greatly improves the cost of color printing. TechEBlog says that the Xerox ColorQube 9200 series of ink can reduce printing costs by up to 62%. Unfortunately, printers that are capable of using this solid printer ink cost $23,000.