  Non-destructive subsurface imaging methods based on the absorption or
scattering of photons or neutrons are becoming increasingly popular in cultural
asset conservation. However, these techniques are limited by physical and
practical issues: their penetration depth may be insufficient for large items,
and they usually necessitate transferring the objects of interest to
specialised laboratories. The latter issue is recently being addressed by the
development of portable sources, but artificial radiation can be harmful and is
thus subjected to strict regulation. Muons are elementary particles that are
abundantly and freely created in the atmosphere by cosmic-ray interactions.
Their absorption and scattering in matter are respectively dependent on the
density and elemental composition of the substance they traverse, suggesting
that they could be used for subsurface remote imaging. This novel technique,
dubbed "muography", has been used in applications ranging from geophysics to
archaeology, but has remained largely unexplored for a wide range of cultural
heritage objects that are small by muography standards but whose size and
density are too large for conventional imaging methods. This document outlines
the general arguments and some early simulation studies that aim at exploring
the low-size limit of muography and its relevance for cultural heritage
preservation.
