An electro-optic display comprises first and second substrates, and an adhesive layer and a layer of electro-optic material disposed between these substrates, the adhesive layer comprising a mixture of a polymeric adhesive material and an additive selected from a salt, a polyelectrolyte, a polymer electrolyte, a solid electrolyte, a conductive metal powder, a ferrofluid, a non-reactive solvent, a conductive organic compound, and combinations thereof. The additive enables the volume resistivity of the adhesive layer to be controlled. Also, in an encapsulated electrophoretic medium comprising capsules in a polymeric binder, the volume resistivity of the binder can be controlled in a similar manner.