Digital BW, The Print

Yes - in UV protection thickness IS the only solution that I have heard of - any so-called thin spray protection boasting of UV in any theory would need to distort color wavelengths - thus changing the color/appearance of the print itself. 

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Ernst Dinkla <edinkla@...> wrote:
>
> Op 2-1-2011 17:54, Paul schreef:
> 
> > By the way, there is another combination of spraying that should be
> > tested.  The Print Shield has a very volatile base that evaporates so
> > quickly that in some hot dry places it hits the paper as hard little
> > balls.  This very volatile base appears to cause it to, relatively,
> > sit on the surface as opposed to soaking in and surrounding the
> > carbon particles and paper base (or coating).
> >
> > Before a large company's threats drove Livick's fade testing off the
> > web, he appeared to find that a combination of the lighter, less
> > volatile Lascaux Fixativ applied first, and then the UV containing
> > Print Shield second improved lightfastness.
> >
> > Whether this was due to the different characteristics of the sprays
> > or just because it resulted in a thicker coat is uncertain.
> >
> > It appears there are somewhat better fade results with the water
> > based UV Eco coating from Premier Art than with the solvent based
> > Print Shield, probably due to the thickness of the coat.  A Golden
> > paints tech once told me that, all else being equal (thickness,
> > amount of UV component, etc.) the solvent based products are more
> > effective.  The water borne ones are like "gooey golf balls," with
> > gaps between them that do not fill in all that well.
> 
> > Paul www.PaulRoark.com
> 
> 
> There are doubts whether UV blocking is possible with the thin layers as 
> produced by for example Print Shield. Much more likely gas fading of any 
> kind is blocked by the varnish.
> 
> Water based varnishes are usually dispersed acrylics and it is in their 
> nature that they have more difficulty to form continuous layers. even 
> harder when the layers are thin. But on canvas with thicker layers the 
> encapsulation should be perfect.
> 
> I have used a Talens varnish 680 that is slow in drying, kind of white 
> spirit based and the prints keep that smell for a long time. On for 
> example HP Matte Litho Realistic the matt surface isn't changed much. 
> Toxic as well though.
> 
> 
> -- 
> Met vriendelijke groeten,   Ernst
> 
> Try: http://tech.groups.yahoo.com/group/Wide_Inkjet_Printers/
> 
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