Impact of protective glass on photodegradation of ink-jet printed documents

Abstract

Ink-jet printing has recently been increasingly used for professional and domestic purposes. However, the degradation of ink-jet prints under the influence of external factors, predominantly light, can cause unexpected problems and lead to the limited life span of a product. It is therefore essential to have in-depth knowledge about the materials, i.e. paper and ink, used for ink-jet printing and to consider their lightfastness to assure the resistance of a print as a whole. The aim of the present research was to study the lightfastness of ink-jet prints protected with glass. Using a printer with dye-based inks, samples of cyan, magenta, yellow and black were printed on different paper substrates. Prints and substrates alone were exposed to the radiation of xenon light for a limited time to simulate the action of average daylight. Some of the samples were exposed to radiation without protection, while others were covered with ordinary window glass or glass which ensured UV protection. Afterwards, the changes on samples were evaluated spectrophotometrically and colour differences were calculated using the CIEDE2000 equation. The results showed that glass effectively reduces the photodegradation of ink-jet prints. Protection with UV glass proved to be more effective than with ordinary glass. The substrate selection was also significant in achieving print lightfastness, as much smaller colour differences were observed on the prints made on photo paper than on those printed on plain office paper.