i experimented using an ordinary arts and crafts bone folder to crease my epson hot press paper so that my pages in a screwpost book lie flat. to minimize the degree of folding, i pressed two parallel lines about an inch away from the post edge. this insures that the paper never folds more than 90 degrees at any one fold line. i find it works best to press the crease on the print side. does anyone fold paper with a burnish bone and if so does the paper eventually tear apart due to repeated page flipping?
