I have noticed that Polaroid Type 59 ER images have a surface structure. White parts are most "indented", black parts are most raised--reflecting the fact that the white has no diffused dye, the black has all three diffused dyes. You have to look obliquely, with light reflected off the surface of the print. (It is most apparent in a patterned section, say a grid.) I assume this is well known, but I have not seen it mentioned. Does anyone know any discussions of this in the literature or the web? Martin Krieger krieger@usc.edu

-- Martin Krieger (krieger@usc.edu), September 14, 2001