The Principal effects of Press drying are presented as one of paper densification and one of increased bonding area at equal density, compared with wet pressing and conventional drying. The increased bonding at equal density is limited to lignin-rich pulps or those containing insufficently delignified parenchyma cells of hardwoods, This is caused by lignin softening at the elevated web temperatures in press drying. There are indications that some auto-crosslinking of wood polymers occurs at the high temperatures, characteristic of the last period of press drying, evidenced by the development of wet strength and swelling restrictions. A number of relevant process parameters involving single-nip and multiple-nip press drying are discussed. Alternative means of densifying paper webs, including calendering and wet pressing with hard nips and breaker stack nips, are discussed with respect to their effect on selected strength parameters. -- AATA