Title
Influence of light and temperature on optical properties of papers
Authors
BARBARA BLAZNIK DIANA GREGOR-SVETEC and SABINA BRACKO

Received March 16, 2016
Published Volume 51 Issue 7-8 July-August
Keywords paper, optical properties, stability, light, temperature, CIEDE2000

Abstract
Paper still represents one of the most significant carriers of information. In order to preserve printed information, the resistance of paper should be considered. The aim of the present study was to examine the cumulative effect of light and temperature on the optical properties of four often used paper grades. Office, recycled, synthetic and permanent papers were examined, and their properties were evaluated based on spectrophotometric measurements after exposure to xenon light at two different temperatures to simulate the conditions of use and storage of documents. Results showed that the effect of temperature alone was not negligible, however, light caused the most evident changes. Paper samples that contained cellulosic and recycled fibres were more affected by the destructive influence of light, a significantly smaller impact was observed on synthetic and permanent papers. Colour differences, which occurred on papers after exposure to light, were calculated using CIEDE2000 equation and they were in agreement with the changes in whiteness and yellowness of the papers.