Re: Seeking Information on 2 problems with Gum process
The secret to using cyanotype as an underlayer without its getting too dark is to properly develop a curve for it. It is a very short stop, contrasty process and either you underexpose it and get no highlights or you expose it correctly and get blocked up shadows. It has to have a curve that flattens the negative considerably. I personally use the PDN system developed by Mark Nelson but there are also other methods to do this I'm sure....perhaps Dan Burkholder has a cyano curve on his website.
However, another option I have been working with is to print the cyanotype layer weakly JUST for lightbox registration purposes, and then using thalo blue as my last layer to print in the majority of the blue in the image. It gives it a more "gummy" look that way and more punch. I have also found that more gum layers give that nice sheen to the image that I love.
----- Original Message ----- From: "cadunn" <firstname.lastname@example.org>
Sent: Wednesday, April 30, 2008 4:50 AM
Subject: Re: Seeking Information on 2 problems with Gum process
Henry wrote: but I found it much better to dilutethe coating solution with anything up to six or seven times its own volume