Various disclosed borehole imaging tools and methods provide an improved high-resolution electrode configuration suitable for imaging in both water-based and oil-based muds. In at least some embodiments, the imaging tools employ a unitary conductive body to provide a wall-contacting face with grooves that define multiple sensing surfaces. Toroids may be seated in the grooves around each sensing surface for measuring the current flow through each sensing surface. Such placement enables a nearly ideal equipotential surface to be maintained and a straightforward “full coverage” electrode configuration due to a minimal electrode separation. Moreover, the disclosed configuration promises robust and reliable performance in the hostile conditions often experienced by logging while drilling (LWD) tools. This wall-contacting face can be provided on an extendable sensor pad or embedded on the outer surface of a LWD stabilizer fin.