Very interesting and informative blog post by Vicky Hanley of the National Museum of Scotland explains how her team used washi in several steps of conserving and mounting vintage railway posters for an exhibition
See Scotland by Train
Read the blog post and see the detailed process images at http://blog.nms.ac.uk/2012/06/08/the-conservation-of-railway-posters-for-the-see-scotland-by-train-exhibition/