IN SEARCH OF A SUITABLE COATING FOR PYROGRAPHY.

This paper presents the results of an experiment made to examine the discolouration of pyrography, exposed to natural light aging, after coating it with one of two traditional surface finishes. Strips of wood material made of English sycamore (Acer pseudoplatanus) were 'scorched' in a controlled manner at various temperatures to produce different shades from light to dark. This method produced consistent and comparable colour scales for the purpose of testing. Samples were then coated with an oil solution, shellac, or left uncoated and exposed to natural light aging for 110 days/nights. Overall, the sample coated with the oil solution returned the lowest colorimetric colour differences for segments 'scorched' at 350°C and above. Yet, from a visual perspective, via microscopy, it was found that the use of either coating was beneficial for the longevity of the surface 'scorching', in comparison to the sample left uncoated. Neither coating seemed to retard fading for pyrography 'scorched' at lower temperatures. However, it must be considered that the use of either of these treatments will eventually reduce contrast in the image as the coatings darken and yellow further in natural light. [ABSTRACT FROM AUTHOR]