Practical guide to photographic & photo-mechanical printing (1887)
Burton, W. K. (William Kinnimond) · London, Marion and co. · leaf 151
131 CONTACT PRINTING should say that the general characteristics of a portrait negative to be vignetted should be the same as those of a landscape negative — softness and delicacy — and that besides special attention should be paid to the background. The commonest background to use for a vignette… … but it is by no means necessary that it be uniform. Any background which is the reverse of conspicuous, which has no tint deeper than a half tone, does well for a vignette. The thing to be particularly avoided is a dark background, or one of a pronounced type. A blanket placed so far behind the…
Photography · Photomechanical processes
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.