The card printing system of the present invention includes a cartridge sub-assembly and a printer sub-assembly. The cartridge sub-assembly encloses a stack of horizontally positioned cards that have each been plied with photosensitive microcapsules. The printer sub-assembly interfaced with the cartridge sub-assembly to obtain a card from the stack. The printer sub-assembly then forms a latent image upon the photosensitive microcapsules upon the obtained card and develops that image by applying a mechanical pressure to the photosensitive microcapsules with a developer array. The develop array is a block containing a number spring-loaded developer balls.