Controversy over artwork's authenticity is ongoing despite numerous technologies for copyright protection. Artists should build their own ways to protect the authority, but these are still open to piracy. Here, a platform is proposed for developing anticounterfeiting labels based on physical unclonable functions (PUFs), in an artist-friendly manner, brushstrokes. Deoxyribonucleic acid (DNA), which is natural, biocompatible, and eco-friendly, can be applied as a paint that shows entropy-driven buckling instability of the liquid crystal phase. Brushed and wholly dried DNA exhibits line-shaped zig-zag textures with inherent randomness as a source of the PUF, and its primary performance and reliability are systematically examined. This breakthrough enables the utilization of these drawings in a wider range of applications.