Humidity Sensitivity of Inkjet Prints

One of the potential aspects of the degradation of digitally printed images is their sensitivity to elevated humidity. Inkjet prints in particular have been shown to exhibit humid bleed. Studies into the humidity stability of inkjet prints have led to the development of an ISO standard to test humidity fastness, published as ISO 18946:2011. This paper details the use of this methodology to examine the humidity sensitivity of a number of contemporary ink-media combinations in use ca. 2000-2010. Two environmental exposure conditions were used: 25 degrees Celsius, 85% RH and 40 degrees Celsius, 80% RH. We find that the extent of humid bleed varies widely depending on the ink-media combinations and the environ-mental exposure conditions. In particular, swellable papers printed with dye-based inks are found to exhibit pro-nounced humid bleed, while plain and archival papers are found to be less susceptible to conditions of elevated humidity. However colorimetric measurements indicate that both pigment and dye-based inks show some colour change when printed on the latter papers. This work provides valuable information regarding the comparative stability of inkjet prints, many of which make their way into heritage collections and archives.

This paper is freely available for download at http://www.morana-rtd.com/e-preservationscience/2012/Fricker-29-06-2012.pdf