The purpose of this investigation was to determine whether exposure to light or ozone increases the sensitivity of some inkjetprinted images to surface cracking during handling. In previous studies, several inkjet print examples showed a potential for significant cracking and flaking of the image area when handled after exposure to light and ozone. In these new experiments both printed and unprinted samples of two glossy porous photo inkjet papers from different manufacturers were exposed in separate experiments to 50 kilo-lux fluorescent and 50 kilo-lux xenon light in increments of time for up to twelve weeks and to 5 ppm ozone for one and two weeks. The exposed samples were tested for cracking according to the procedure described in ISO 18907 "Imaging Materials – Photographic Films and Papers – Wedge Test for Brittleness". The samples were evaluated visually both with and without magnification to determine the wedge diameter where cracking is first seen. The samples were also measured with a Gretag Spectroscan to determine if the increase in cracking came before or after noticeable colorant fade or paper yellowing occurred. Even though the two papers selected for this study were the same type, they behaved entirely differently. One paper showed sensitivity to crack before exposure and increasing propensity to crack with exposure to light and ozone. The other paper was not sensitive to crack before exposure and only after twelve weeks exposure to xenon light showed surface disintegration. Because of this, it is difficult to reach general conclusions that represent the entire spectrum of inkjet print media. Additional work is needed to provide a more complete picture of brittleness behavior of these materials after exposure to light and ozone.
Eugene Salesin, Daniel Burge, "The Cracking of Inkjet Colorant Receiver Layers on Exposure to Light" in Proc. Int'l Symp.on Technologies for Digital Photo Fulfillment, 2012, pp 13 - 16, https://doi.org/10.2352/ISSN.2169-4672.2012.3.0.44