A method of manufacture of a strain gage or flexible polyimide-based resistor, the method including the steps of providing a flexible polyimide substrate, joining a conductive foil to the flexible polyimide substrate, applying a layer of photoresist to the conductive foil and thereafter, patterning the conductive foil by etching using the photoresist, wherein the method is characterized in that it includes at least one of the following steps: surface conditioning of the flexible polyimide substrate using mechanical abrasion, scrubbing of the conductive foil prior to the patterning, removal of photoresist by scrubbing following the patterning, pressurized cleaning, using deionized water, following the patterning, automated algorithmic resistance calibration and shunt trimming and forming an emulsion layer of epoxy over the conductive foil following the patterning.