Chrome Guide and Posimatte, neutralizing components

Positive Chrome Guide was easy to construct as the positive diazo and dye mixed nicely and produced stable coating.      Negative working system was another story.       Negative diazo was less stable than positive diazo and reacted readily with dyes.        In color proofing system much higher level of dyes were needed for an intensive colors required for imaging.       Therefore the dyes caused premature aging and the discoloration.        It was necessary to neutralize the dyes to avoid such issues.      Understanding the mechanism Al Deutsh suggested to react the dye with the component used for the "V" coating.        In many of our subsequent  plate patents extensive  references are made for the use of a D-11 dye.      This is one of the side benefit of Chrome Guide research as we understood the chemistry and interaction of diazo sensitizer and dyes thoroughly.        Even in the positive system, we found neutralizing the dye was useful.       Posimatte positive plate featured very high print out image due to the big contrast between exposed and unexposed area made possible by our experience and understanding in Chrome Guide dyes.           Interestingly European market preferred strong image contrast After the development rather than Before, so the strong print out feature worked out by Jim Shelnut was never incorporated in European product line and found acceptance only in the US market.