A plurality of edges of a transparent sheet are adhered to a back of a paper backing to from a clear-front envelope. When estimating a ratio of pilot power to traffic power, a problem caused by an unevenness of the power ratio is prevented. Energy is imparted to the pattern-forming material in an imagewise manner to form the conductive material layer. The flash card reader includes a CompactFlash connector, coupled to the IDE converter, for receiving a CompactFlash card through a single slot in the single-slot multi-flash-card reader, the CompactFlash connector making electrical connection with the CompactFlash card for signals in the CompactFlash interface. The first and second intermediate cuts and the outer-shoulder cuts, respectively, mutually converge at an angle of about 20\xb0 and are axially offset from each other and circumferentially distributed in an alternated sequence, to delimit continuous rest surfaces, an intermediate and outer-shoulder surface respectively, with an undulated course.