A Palm-Size Pocket Photo Printer
More than with most other types of printers, the size of these pocket photo devices is dictated primarily by the dimensions of the media on which they print. The Kodak Step Slim, for example, measures 0.9 by 3.3 by 4.9 inches and weighs just over half a pound. As mentioned, it uses 2-by-3-inch paper, joining the PCMag Best of 2019 winner the HP Sprocket Photo Printer, and the Polaroid Hi-Print Pocket Photo Printer.
That Polaroid is a dye-sublimation device and therefore slightly larger than most of its Zink competitors. Rather than applying ink to paper, Zink devices use special paper embedded with color crystals that react to heat patterns generated by the printer. Dye-sub printers use more conventional paper and an ink-impregnated carrier film, typically bundled together in refill cartridges. Zink printers are faster, producing an image in one pass through the device; their dye-sub rivals make four passes through the paper path.