Digital BW, The Print

David,

> 
> Watercolor papers are made from cotton, not wood, and those manufacturers
> who have been in the business, some for 500 years or more, know precisely
> what they are doing when selecting raw materials.

The general assumption is that watercolor papers are 100% cotton, but that is not always the case. Alpha cellulose papers can and are sold as watercolor paper. What you want are ligin and acid free cotton papers, however many Japanese papers are made from rice plant fibers or mulberry  wood and are highly regarded by fine art print makers and alt process printers.

In the case of alt. processes which are feric based such as platinum/palladium, kallitypes, agyrotyes, and van dyke brown the preferred pH is acidic. On the other hand water colorists prefer papers with an alkaline buffer. I'm not convinced that an alkaline buffered paper is good for ink jet printing as well as an acid paper. pH neutral would probably be the best solution for ink jet printing but the coating pH as well as the humidity will definitely play a role in any printing process.

So are you checking the paper pH? Are you controlling the humidity in your paper storage and printing area. How old are the papers you are using? These things are important. As Eric points out, smaller batches are probably prefered.

I've had ink jet papers yellow just sitting in sealed packages which was visible on the verso (or uncoated side of the paper) while the coated side remained white. These papers contained OBAs.

But I've also had buffered art papers (100% non alpha cellulose)change color with age. Which leads me to comment that all papers change color with age.  I believe Leonardo Di Vinci was quoted as saying, "Time and water change all things.", though I have yet been able to find the quote in print, so that attribution maybe legend. Yet the logic of the quote holds and is very applicable to printing papers.

>
You are claiming that watercolor papers are not
consistent, 
>

Yes.

>
therefore coated papers must be reliable?
>

No.

@Paul Roark

In the early days of giclee ateliers such as Nash Editions, ink jet printing was considered an alternative process. Now it has become mainstream. Typically only antiquarian printing techniques and process are considered alt. including silver gelatin.

I know the logic is that modern ink jet printing is a primarily carbon pigmented based so therefore there is a linkage to historical carbon pigmented printing but in my book that's bit of a stretch, not to mention dye based inks. I'm not suggesting that ink jet printing is passe or insignificant because of it's relatively short history; certainly artist/printers such as Richard Benson (being a widely known and highly regarded printer of many disciplines) has elevated ink jet printing to a fine art genre. And there are others of course in that elite group such as yourself, Tyler Boley, and Jon Cone. I'm just sayin ...

Regards,

Don Bryant