An RFID label includes a release liner having an opening or window, to allow placement of an interposer through the window, and in contact with end portions of an antenna. By coupling the interposer to the antenna through the window in the release liner, the coupling may be performed at a later point than usual in the fabrication of the label. This allows the label to be fabricated with less wear and tear on the interposer, which is a relatively expensive and fragile part of the antenna. In addition, testing of the interposers before applying them to a web of labels may save costs by eliminating waste of material. Testing of the straps alone can allow prediction of performance of the finished label.