Abstract: Produce a printing paper that offers sufficient bulk and flexibility by using a bulk-increasing/softening agent with a HLB of 6 or below, which is either a liquid or a solid with a melting point of 40° C. or below, wherein the agent may be an ester compound of polyhydric alcohol and higher fatty acid or a long-chain alkyl ammonium salt, and by adjusting the surface temperature of the paper during a preheating drying period (a period during a drying process before the temperature of a wet paper becomes constant) to at least 10° C. higher than the melting point of the bulk-increasing/softening agent.

Abstract: The present invention is a thermally sensitive recording medium which has excellent anti ultra violet ray property, mainly composed of an electron donating compound and an electron accepting compound, containing at least one of benzoxadinone compound represented by general formula (1) as an ultra violet ray absorbing agent. In the above mentioned formula, R represents hydrogen atom, hydroxyl group, alkyl group of carbon number 1-8, alkoxy group of carbon number 1-6, acyl group of carbon number 1-6, acyloxy group of carbon number 1-6, alkoxy carbonyl group of carbon number 1-6, carboxyl group, halogen atom or nitro group and X represents a divalent group or a direct bond.

Abstract: A phenanthridine derivative metal complex of formula 1 having a large absorption in the near-infrared range and a reduced absorption in the visible range, which phenanthridine derivative metal complex is used in a transparent recording medium: ##STR1## where M is a metal atom, and X is a negative ion.

Abstract: An acridine derivative metal complex of formula 2 having a large absorption in the near-infrared range and a reduced absorption in the visible range, which acridine derivative metal complex is used in a transparent recording medium: ##STR1## where M is a metal atom, and X is a negative ion.

Abstract: An acridine derivative metal complex of formula 1 or formula 2 having a large absorption in the near-infrared range and a reduced absorption in the visible range, which acridine derivative metal complex is used in a transparent recording medium: ##STR1## where M is a metal atom, and X is a negative ion.