We report on a novel process based on photoinduced C,H-insertion crosslinking (CHic). Upon activation by UV light or near-infrared light, the material system requires only aliphatic C,H units, which are ubiquitous, as reaction partners to generate stable crosslinked structures. Therefore, CHicable pre-polymers can be conveniently designed to various properties and generated on a wide range of materials. Moreover, the CHic process allows the simple incorporation of complex molecules, enabling the generation of a broad spectrum of functional structures in a very simple way.