Digital BW, The Print

I printed an image of a cholla plant using MIS FSN quad and the 
Piezo plugin on Eclipse Satine Bright White (EcSAT) since I have a 
bunch of it. The cholla plant had a fairly dark (near black) 
base/shadow that could be reproducibly measured.  EcSAT in my hands 
doesn't have much of a dmax unless you really up the amount of ink 
that is layed down. In this case the Piezo settings were a gamma of 
0.98 and a dot gain of 110% Each print except the control was 
sprayed with one of four spray varnishes. Each print received two 
light sprayings allowing about five minutes minimum between coats. 
All sprays were Krylon products except, obviously, the Lyson print 
Guard.

I used an image rather than a step wedge because I was particularly 
interested in what spraying would do to the over all appearance.

The purpose of the experiment was to put a protective coating on the 
injet receiving layer to prevent flaking. I really don't like the 
idea of rubbing since I don't know how it will effect the coating. 

I measured the density, red, green and blue reflectance with an 
Eseco Compumaster TLS-90S. The results are in the table.

               Paper Base				
SPRAY	                       D	R	G	B
None	                       0.04	0.04	0.03	0.01
Kamar (1312)	               0.05	0.06	0.04	0.06
UV Resistant Clear (1305)      0.05	0.06	0.03	0.02
Workable Fixatif   (1306)      0.04	0.05	0.03	0.02
Lyson Print Guard	       0.04	0.04	0.03	0.01


               Base of Cholla				
SPRAY	                       D	R	G	B
None	                       1.22	1.25	1.24	1.2
Kamar (1312)	               1.58	1.61	1.61	1.53
UV Resistant Clear (1305)      1.55	1.56	1.57	1.5
Workable Fixatif   (1306)      1.31	1.33	1.34	1.3
Lyson Print Guard	       1.38	1.39	1.39	1.35

All of the sprays increase the dmax of the print to one degree or 
another with Kamar having the greatest effect. It was obvious to the 
eye that the blacks and dark grays darkened when sprayed. I allowed 
the prints to dry a day before measuring them so the effect seems to 
be permananent. It would also appear that there is a minor, probably 
negligable, change in the color of the paper base due to the 
spraying.

The degree of darkening doesn't seem to be especially predictable 
but if one were going to use an overspray as a protectant it would 
be important to start with a lighter than normal print and one would 
most likely want to have to have a separate dot gain setting for the 
monitor in order to predict the final printed result. 

The change in appearance of the print after spraying is not at all 
displeasing and the surface does not have an obvious plastic or 
coated look to it. It is, however, another variable in an already 
muddled process.

At this point I'm not completely convinced this is worthwhile. 

If anyone would like to see the image I used I will e-mail a jpeg of 
it to you on request or, within reason, I would be willing to send 
copies of a sprayed and a control image to those interested if you 
send me a stamped preaddressed letter sized shipping envelope. I 
don't have a web site so I can't post them.

Roger