To provide a base paper for a cut form for press bonding postcard free from jamming trouble in printers, having excellent transportability and high adhesive strength between the adhesive composition layers.

The self-sealing base paper suitable as a base paper of a cut form for press bonding postcard has adhesive composition layers containing a pressure-sensitive adhesive base and formed on both faces of a paper substrate to form a releasing face at one surface and a non-releasing face at the other surface. The base paper has an air permeability of ≤300 sec in conformity with JIS P 8117, a static friction coefficient of ≤0.75 in conformity with JIS P 8147, and a water content of the sheet of 3.5-6.5 wt.%.