A printing foil for foil printing a region of an image comprising:a substrate;a layer of foil bonded to the substrate; anda layer covering the foil which layer is formed from a material chosen from the group of materials consisting of methacrylic copolymer resin, polyester, polycarbonate and polyvinyl chloride. The AD converter is configured with an AD conversion unit which is a charge sharing type and performing successive approximation, a digital correction unit which receives a digital output of the AD conversion unit and performs digital correction to the digital output, and a holding unit which holds a test signal. A first embodiment includes a plurality of embolizing elements fixed to the carrier at spaced-apart intervals along its length.