Four samples of modern transparent paper, both new and artificially aged, were humidified by immersion, a Gortex marination sandwich, or a humidity chamber. Afterwards, they were flattened either by a conventional blotter press or on a suction table. They were tested for moisture absorption, gloss, transmission, and opacity. Scanning electron microscopy imaging showed changes in surface morphology of one of the papers. Dimensional changes and the results of tensile tests are shown as graphs. All three humidity techniques caused some changes in the dimensions of the papers. Immersion caused the greatest optical and mechanical changes. Experimental procedures and instrumental analysis are given in the detailed appendix.