A method for using a radio frequency identification (RFID) system including a transponder, an antenna, and a reader, the antenna coupled to the reader, the antenna and the reader for transmitting a radio signal to the transponder and for receiving a response radio signal from the transponder, the response radio signal including data from the transponder, the method including: selecting a curtain that limits propagation of the radio signal; and placing the curtain in an area through which the radio signal would otherwise propagate; wherein the curtain includes a plurality of flexible strips transparent to visible light, the long edge of each of the strips is oriented in substantially the vertical direction, more than one strip overlaps a portion of the width of an adjacent strip along the length of the adjacent strip, and the length of each of the strips is substantially greater than the width of each of the strips.