We describe the development of micro-porous paper that meets the demands on print-quality in different types of digital printing. The paper contains a micro-porous layer that has a surface pore diameter of 0.5 to 30 μm and a density of 0.2 to 0.5 g/cm³. The micro-porous layer can be easily obtained by coating a sheet substrate with a resincontaining liquid stirred forming bubbles. Application areas for the micro-porous paper in digital printing include thermal wax transfer, thermal dye diffusion, direct thermal, solid inkjet and toner-based marking.In the first application, the micro-porous layer acts as an ink-receiving layer (see Figure 1) due to the heat-insulating nature, the compressibility and the surface structure. The micro-porous paper has a thermal conductivity of 0.25 W/(m˙k) or less. The compression stress of the micro-porous layer under a compression of 10% by volume is controlled to 8 kg/cm² or less. The molten ink permeates sufficiently into the region of the micro-porous surface layer due to the presence of a large number (3,000/mm² or more) of fine pores distributed on the surface. Thus the micro-porous surface layer enhances color density, dot reproducibility and continuous tone reproducibility in this application.