An air-bearing slider used in a magnetic recording disk drive has a surface that supports a magnetoresistive (MR) read head or sensor and an electrical lapping guide (ELG) adjacent to the MR sensor. The ELG is formed of a different material than the MR sensor so as to have both a high electrical resistivity and a substantially higher etch rate. When the ELG and MR sensor are etched simultaneously to form their respective back edges, the ELG will have a sharp well-defined non-tapered wall at the back edge. The ELG has a film thickness close to but generally thinner than that of the MR sensor, and a sheet resistance to generally match the resistance measurement capability of the lapping tool. The preferred material for the ELG is an alloy comprising silver (Ag) and one or more of Sn, Ge and zinc Zn.