Tommi KAPLAS, Kari LAITINEN¹, Tuula MOILANEN^*, Yrjö TOLONEN², Kristoffer ALBRECHT¹, and Raimo SILVENNOINEN^†

University of Eastern Finland, Department of Physics and Mathematics, Joensuu Campus, P. O. Box 111, FI-8010 Joensuu, Finland
¹Aalto University, School of Art and Design, P. O. Box 31000, 00076 Aalto, Helsinki, Finland
²Mikkeli University of Applied Sciences, P. O. Box 181, FI-50101 Mikkeli, Finland

(Received August 27, 2009; Accepted February 26, 2010)

Traditional Japanese woodblock printing is a centuries old art form. This time-honoured form of art is at risk of extinction as a consequence of the increasing lack of availability of wild cherry trees, which are a traditionally used woodblock material. Solutions for this material problem have been investigated for several years, but none of the tested materials has been sufficient when compared with the watercolour print quality imprinted by wild cherry woodblocks. To contribute to overcoming this material problem, we have investigated the physical properties of heat-treated woodblock materials made from different wood species. The International Commission on Illumination (CIE) tristimulus values, the CIELAB coordinates, the total reflectance, and the gloss, as well as, the water contact angle from the woodblock surface is observed to have a strong relation to the surface treatment of a woodblock. The surface treatment of a woodblock, in turn, relates to its water delivery, which is the basis for watercolour printing.

Key words: diffractive optical element, permittivity, optical roughness, Japanese woodblock print, heat-treatment

^*Present address: Honen-in-cho 84, Sakyo-ku, Kyoto 606-8421, Japan.
^†E-mail address: Raimo.Silvennoinen@uef.fi