Re: VDB & Hi from New Orleans
Sandy, I would agree regarding moisture.... I think the moisture content of the paper/emulsion at the time of exposure is quite critical when working with PT/PD and I am sure other processes. The books that I have read have little to say about this variable. If anyone knows of any book or articles that does cover it well, I would be interested in reading it. A number of years ago I began to pre-humidify my paper before coating and also to track the drying time after coating and before exposure.... this gave a much better coating and much more consistent results. Recently I have been working with the Kozo paper from Bostick & Sullivan and was amazed at how much moisture this thin paper will soak up and hold on to... it almost seems hygroscopic. Greetings to any list members in New Orleans. I just got here today and will be here for a week—coffee anyone? A baby cried so much on the flight down from Chicago I was about ready to offer to breast feed the child myself to get some peace and quiet. Mark Nelson Precision Digital Negatives PDNPrint : Precision Digital Negatives Mark I. Nelson Photography In a message dated 11/5/07 11:07:56 AM, sanking@clemson.edu writes: Mark, As Don mentioned, there are many ways to work VDB with good results. As to why double coating works better, one line of thought is that it just puts more moisture in the paper. For example, if you just coat the paper with plain distilled water, let dry, and then apply a coat of sensitizer, you will often see an increase in Dmax. All of this depends on how long you let the paper dry, drying conditions, etc. However, like Loris I have found that I get as much or more Dmax by single coating and then toning before fixing. Yes, toning changes the color of native VDB, but then again a toned VDB should be theory be much more archival than an untoned one. BTW, I used to always double coat, but I found that with palladium and kallitype it was much more difficult to remove the stain than with single coating. I don't have any trouble with stain with VDB so in theory could double coat all the time, just don't find it necessary. Sandy King ************************************** See what's new at http://www.aol.com |