Solar flare reconnection is widely understood to occur in the thin current sheet separating antiparallel open field lines. It is also commonly believed that instabilities (such as tearing-mode or Kelvin-Helmholtz) in this layer play a central role in driving flare reconnection. However, any small-scale instabilities responsible for reconnection occur on scales not resolved by current coronal imaging, leaving their spatial and temporal properties poorly constrained. This observational gap presents significant challenges to investigating fundamental reconnection mechanisms. Flare ribbons, on the other hand, represent the chromospheric footpoints of freshly reconnected field lines and are easily identified in FUV/EUV flare observations. Previous observational studies strongly suggest that the morphology of a flare ribbon represents an image of the coronal reconnection, projected onto the chromospheric plasma. We demonstrate a novel method to invert this projection, recovering indirect images of the evolving current sheet from the ribbons themselves. Through these reconstructions, we recover the spatial scales of underlying instabilities.