We feature the recent developments of patterning of functional polydiacetylene (PDA) on a paper substrate that can be fully integrated with conventional inkjet printing techniques. The use of the paper substrate facilitates the fabrication of flexible, lightweight, and disposable devices. The PDA systems loaded on paper display their uniquely optical properties. In general, diacetylene ink solutions are inkjet-printed on paper and the subsequent UV-irradiation induces photopolymerization of self-assembled DA molecules, leading to the blue phase PDAcoated paper film. The typical blue-to-red transition of the PDA paper film undergoes when it is exposed to a variety of external stimuli. We introduce three types of ink formulation protocols to prepare the PDA precursor solutions that are compatible with inkjet-printing. We also represent the PDA printed paper system and their practical applications, such as counterfeit-proof ink, electrothermochromic paper display, and human sweat pore mapping.