paper types and target LAB values
by Juris Valdmanis
Hello dear list members.
First of all I would like to thank everyone who helped me last time I
asked my questions! Your help was valuable!
But now I have more questions regarding printing to ISO.
In ISO documentation there are Lab target values for primary and secondary
colors for different paper types.
As we are sheet-fed printers we are interested only in paper type 1(gloss
coated), type 2 (matt coated) and type 4 (uncoated white).
As I understood from documentation (I have only an old english version of
ISO 12647-2 and english is not my native language as you may already
realized) all papers what we use for printing I have sorted in these three
types of paper.
But from documentation papers type 1 and type 2 have the same Lab target
values for primary and secondary colors. From my previous conclusion
papers like fine gloss (with 3 coating layers) and rough matt (with only
one coating layer) have same Lab target values.
No problems with type 1 (gloss) papers, as we can get very close to target
values and densities are ordinary.
But for mate papers (type 2) we have to rise densities to get acceptable
Lab values. It could be understandable as paper surface is rougher and you
have to apply more color to get same saturate colors as on paper type 1.
Problem is that higher densities however lead to different problems in
postpress as paper is not drying well and it smears.
Did I understood correct ISO documentation or am I missing something?
And also I did not find answer to another question: Are Lab target values
for wet or dry colors?
Thank you, everyone.
regards,
bebris
14 years, 2 months
- 5
- 7