Digital BW, The Print

If you are interested in the longevity of your print the answer is 
yes.  Many people pay attention to print lifetime measurements by 
Wilhem. But in my view his measurements are unrealistic for most 
situations because they are based on experiments using fluorescent 
light. Daylight contains much harsher wavelengths of light that 
damage inks more quickly. If you are interested in real measurements 
of expected lifetimes for prints displayed in the home that are 
exposed to daylight please see the approach used on this website: 
http://www.livick.com/welcome.htm Their data clearly show how 
misleading the Wilhelm results may be. Their results also show the 
importance of overcoating prints with protective spays. There is a 
lot of great data on their website and some interesting reading about 
their artistic approach.

There are other reasons to spray prints. If you are printing on 
plastic type papers (Epson premium lustre) there are spays (Premiere 
Art Spray ) that minimize gloss differential and are useful even with 
the new epson K3 inks. I have found that the MIS ultratone inks can 
be significantly enhanced on epson lustre paper by using Golden 
Archival varnish spray. Without the spay the deep blacks are weak and 
have an almost foggy like appearance. After 1 coat of spary varnish 
the dmax is significantly enhanced to 2.3.  (using the IJC RIP.) The 
difference is like night and day. Unfortuantely, The golden varnish 
with the MIS UT inks makes the gloss differential worse. But I am 
willing to live with it because I love the emotional effects that 
deep blacks can create in my prints. I have yet to try other spays 
but hope to in the near future.

I know overcoating prints has been talked about many times before on 
this forum but I think it is something we should be spending more 
attention with.