Graphene is a sheet of carbon just one atom thick with truly extraordinary properties, and some of those come from its two dimensional shape. That shape is also why researchers have been looking at it as a coating in order to craft materials with controlled conductivity and wettability. However researchers at MIT have discovered that depositing graphene on to a substrate does not always give the desired results.
Wettability is the ability of something to get wet with extreme examples being superhydrophilic materials that love getting wet and superhydrophobic materials that repel water. Previous work has shown that if you coat materials with graphene, it is the underlying substrate's wettability that determines the wettability of the entire package, but this effect was not studied at the extremes, until now. The MIT researchers have discovered that graphene is not perfectly transparent to a superhydrophobic or superhydrophilic material's wettability. Instead the researchers describe it as translucent, which is a problem for those hoping to coat electronics with graphene to prevent water damage.
Overall though, this may not be a problem as it demonstrates a more complex interaction between the graphene and substrate occurs. As understanding of this interaction grows it should be possible to take advantage of it for new, more interesting purposes.