responding free radical, DMV. It would destroy the CT complex and lead to the formation of aggregate consisting of DMV itself, turning the color from red to purple. However, DMV was unstable in the atmosphere and spontaneously oxidized by O2 under the catalysis of glucose oxidase (GOx), resulting in the recovery of the color. Thus, a temporary pattern can be obtained by “writing” or “drawing” with SDT on the red-colored CT gels. More importantly, the temporary pattern is well repeatable and its lifetime can be modulated by the concentration of SDT, GOx, or glucose. Similarly, A. Quintard and coworkers prepared a self-erased writing by using a trichloroacetic acid (TCA)-driven reaction network. [64] Upon the addition of TCA, the NH2-containing organogelators were immediately protonated, converting the green gel into a yellow sol. (Figure 10b) Meanwhile, the alkaline amine groups of organogelators can catalyze the decarboxylation of TCA, yielding volatile CO2 and CCl3. The decrease of acidity induced the recovery of the green gel without any residual. Hence, temporary words or patterns can be repeatedly written on the surface of the green gel by the addition of TCA. Furthermore, except for writing on the gel surface, it was reported that the gel itself can be applied as self-erased ink as well. J. Jiang and L. Wang et al. presented a writable temporary gel, the precursor of the temporary gelator was a star-shaped molecule containing four carboxyl groups. [65] (Figure 11a) The addition of EDC crosslinked the precursor by catalyzing the condensation of the carboxyl groups, yielding a pulpous and plastic hydrogel. After a while, the anhydride bridges formed by the condensation of carboxyl groups slowly hydrolyzed, causing the collapse of the crosslinking network structure as well as the hydrogel. Due to its good plasticity, the hydrogel showed a good application in 3D printing. Materials in which fluorescence can be temporarily changed by the drive of chemical fuel are also potential self-erased inks. Therefore, the temporary fluorescent emission aggregate reported by D.-S. Guo and coworkers should also be noted. [66] The AIEgens shown in Figure 11b can generate significant fluorescent emission after co-assembly with DNA. However, the DNase I that existed in the solution led DNA to slowly decompose to oligonucleotides, bringing about the disappearance of the fluorescence. Although the author did not provide direct experimental evidence to illustrate its application in self-erased ink. It is still to be expected that this solution can be used in transferring confidential information.