Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "john" <deanwork2003@...> wrote:
>
> Mark,
> 
> What do you know about the brighteners being used by Breathing Color in their Chromata canvas products? I've been meaning to ask you that for a year now.

Inspection by UV blacklight reveals that the Chromata White Canvas has no fluorescing compounds in the coating, but somewhat surprizingly there are OBAs in the canvas itself. This is another example (its not just Breathing Color) that will refer to a product as OBA free when they really mean none are present in the top coat.  Usually, products that are OBA-free in the top coat do pretty well in my tests even if they aren't technically OBA-free. 

You will learn pretty much what you need to know by looking at the UV-included/UV-excluded measurements I make on the samples in test at AaI&A. That information is listed in a table on the description page in each report.  When the delta b* values calculated by comparing the UV-exc/UV-inc measurments (also listed in the tables) is less than approximately 3.0, OBA burnout from light exposure of gas fading won't result in strong "discoloration" but for papers that tip the scales over 3.0 in these tables I provide, one is wise to consider alternative papers if longevity and freedom from preferential edge discoloration is important to you.

kind regards

Mark
http://www.aardenburg-imaging.com