AIC 53rd Annual Meeting

This study focuses on the use of microfading tests (MFT) in transmission mode under a microscope to evaluate the lightfastness of screen additive color processes on flexible supports that followed autochrome after the 1920s, such as Alticolor, Filmocolor, Dufaycolor, etc. These early color photographs, based on a combination of colored grains or lines, are sensitive to light and tend to fade. Traditional MFT methods typically cover areas containing hundreds of color grains, resulting in an average color change that does not accurately represent the fading behavior of each primary color (red, green, blue) individually. In addition, most MFTs operate in reflectance rather than transmission mode, which allows for a more accurate examination of the effect of light on the inner colored layers of these photographic materials. This study aims to address these limitations by using the MFT in transmission mode to better understand how light exposure affects each color component separately, thus providing a more detailed assessment of the stability of these historical coloring processes. The results of this study will provide valuable insights into the conservation and preservation of these fragile colored materials.