Elcom resistive touch screens are constructed using two flexible layers of optical quality polyester that have been coated in a nearly invisible metallic film. These two layers are evenly separated from each other by tiny spacer dots and are then sandwiched between a glass substrate and a protective scratch-resistant surface layer. A small electrical current (4-6 volts DC at less than 60Ma) is passed through the metallic coated layers and when a user touches the screen, the two layers make contact in that exact spot. The change in the electrical field is noted at that point by the touch controller.
Once the coordinates are known, a special driver translates the touch in a similar manner to how a mouse driver translates a mouse click.