the patterns are able to maintain their shape, electrical conductivity and adhesion to their respective substrates. Printing conductive patterns directly on to conventionally non-functionalised surfaces such as those for candies allows for the fabrication of small form factor devices which will be further demonstrated in the following section.

We note that the properties of the water-assisted conformally printed structures may be affected by the roughness of the target substrate. We take average roughness (R$_a$) measurements *via* profilometry of the various above-mentioned substrates and find that increased R$_a$ is correlated with increased R$_s$ of single-layer water-assisted conformal patterns; Fig. \[panel3\]i. This is attributed to the printed patterns taking on the different unique morphologies of the respective substrates. The process we present is a proof-of-concept demonstration of conformal printing. One particular area for further work is in effective registration of the functional patterns. To achieve this, two strategies that are compatible with our process and could potentially be used are the water-level lowering method [@Saada2017] or automatic registration using robotics [@LeBorgne2017].

Applications of water-assisted conformal printing
-------------------------------------------------

We have already shown that water-based conformal printing can be used as a simple and effective method to create functional printed patterns on to different 