Researchers at Karlsruhe Institute of Technology (KIT) have developed erasable ink for 3D printing. The researchers created an ink with reversible bonding, meaning that its building blocks can be separated from each other. When the printed structure is immersed in a chemical solvent, it dissolves and can be re-written, meaning that the structure can be modified again and again. Read more at 3DPrint.com: http://3dprint.com/173124/kit-3d-printing-erasable-ink/