Digital BW, The Print

Louis de Stoutz wrote:

>
>I understand that, and also from UV. My point is another one: we use 
>archival paper and archival pigments. What tells me that the probably 
>complex components of a varnish are in themselves archival too? That the 
>varnish will not deteriorate? That its chemicals won't deteriorate the 
>print? That it won't get brittle and take pieces of ink with it? etc.
>
>(I sometimes also wonder about the coatings that are applied on 
>otherwise very archival papers.)
>
>Does Wilhelm test varnishes too?
>
>Louis
>
>
>  
>
Wilhelm tested one varnish and it increased the fade resistance of the 
pigment inkjet inks. You can find it in the data of recent tests. Livick 
also tested varnishes and gets better results too.

Modern resins do have better qualities than what we were used to. 
Yellowing in time doesn't have to happen, flexibility is kept etc. What 
is important is that the inkjet print itself has a high risk of getting 
damaged, mechanically and chemically (oxidation, humidity, other gas 
fading). The varnish gets that at a better level. With traditional 
printing and painting techniques that produce a tough layer there may be 
less gain in better protection by a varnish than what a varnish does to 
inkjet prints. Matte pigment inkjet prints especially are quite easily 
damaged as the bond between pigment/medium/coating/paper isn't high, the 
pigment particles not really embedded in a strong layer. Adding a 
varnish that offers mechanical protection, enhances the bond and lowers 
oxidation/gas fading. The Epson acrylic resin encapsulation of the 
pigment particles is another method.

UV protection is possible with a varnish but a varnish doesn't have to 
have UV protection in the first place as the prints discussed here are 
exposed to indoor light mainly and that's also how Wilhelm tests his 
samples. UV fading may only contribute 15% at most in the fading indoors 
as tested, the rest is visible light fading, gas fading etc.

Ernst