  Security labels combining facile structural color readout and physically
unclonable one-way function (PUF) approach provide promising strategy for
fighting against forgery of marketable products. Here, we justify direct
femtosecond-laser printing, a simple and scalable technology, for fabrication
of high-resolution (12500 dots per inch) and durable PUF labels with a
substantially large encoding capacity of 10$^{895}$ and a simple
spectroscopy-free optical signal readout. The proposed tags are comprised of
laser-printed plasmonic nanostructures exhibiting unique light scattering
behavior and unclonable 3D geometry. Uncontrollable stochastic variation of the
nanostructure geometry in the process of their spot-by-spot printing results in
random and broadband variation of the scattering color of each laser printed
"pixel", making laser-printed patterns unique and suitable for PUF labeling.
