Abstract: To permit adhesion of a strain gauge grid applied to a high temperature plastic, such as a polyimide, the side of the strip of polyimide which is to be attached to the support frame, the strain of which is to be measured, has a solderable surface applied thereto which consists, essentially, of three sublayers, as follows:A first sub-layer of from 1 to 8 .mu.m thickness of chromium nickel alloy, containing, for example, about 20% (by weight) of chromium, or an iron chromium nickel alloy containing, for example, about 50% iron, 49% nickel and 1% chromium (by weight);a second sub-layer of at least about 5 .mu.m thickness, preferably about 7.5 .mu.m thickness of nickel and a third outer sub-layer of gold, for example, between about 4 to 10 .mu.m thick, preferably, about 7 .mu.m. The various sub-layers are applied, for example, after cleaning of the element with a volatile hydrocarbon, or toluol, by vapor deposition, for example, vaporization from a tungsten boat of the respective materials.