Problem with printing correct color

[Dave Carter]

I need your advice on a printing problem.

I have an Epson 4880 printer that I use to print about 16" x 20" pictures using either the Epson canned profile or my Eye One Profile.  The paper is either Epson singleweight matte or sometimes Epson premium Semigloss.  The picture files are provided to me from an artist that develops them in Photoshop.

My problem is she is VERY concerned about VERY small changes in color.  I always send test prints for approval before making the first batch.  And I also run a nozzle check on the printer before printing a batch.  After the first batch, she may order more several months later and sometimes complains that they are different even though I use the same paper and profile.  I keep one original batch print, but can not see the difference that she does.  Although, I have to say, I do not see some colors all that well.

What I am thinking of doing is placing on each picture file a test panel of maybe 2 gray dots and 2 colors from the print.  That way I can measure each batch and know if they are repeating exactly.  (see attached picture).  I can measure the dots using my Eye One Share.  

Do you think this will tell me if batches are exactly the same?  Or, is there a better way to know I am printing the same as the first batch?  Do I need 4 or more targets, or would one pure gray one do?

Thanks for any advice.

Dave

[attachment=17967:031_Peon..._printed.jpg]

[walter.sk]

I need your advice on a printing problem.

I have an Epson 4880 printer that I use to print about 16" x 20" pictures using either the Epson canned profile or my Eye One Profile.  The paper is either Epson singleweight matte or sometimes Epson premium Semigloss.  The picture files are provided to me from an artist that develops them in Photoshop.

My problem is she is VERY concerned about VERY small changes in color.  I always send test prints for approval before making the first batch.  And I also run a nozzle check on the printer before printing a batch.  After the first batch, she may order more several months later and sometimes complains that they are different even though I use the same paper and profile.  I keep one original batch print, but can not see the difference that she does.  Although, I have to say, I do not see some colors all that well.

What I am thinking of doing is placing on each picture file a test panel of maybe 2 gray dots and 2 colors from the print.  That way I can measure each batch and know if they are repeating exactly.  (see attached picture).  I can measure the dots using my Eye One Share.  

Do you think this will tell me if batches are exactly the same?  Or, is there a better way to know I am printing the same as the first batch?  Do I need 4 or more targets, or would one pure gray one do?

Thanks for any advice.

Dave

[attachment=17967:031_Peon..._printed.jpg]

Before you start to drive yourself crazy, find out what are the viewing conditions she has, especially whether they are consistent.  I assume your viewing conditions are consistent as well.  Her small changes in color may be the result of changes in her lighting.

[Dave Carter]

Before you start to drive yourself crazy, find out what are the viewing conditions she has, especially whether they are consistent.  I assume your viewing conditions are consistent as well.  Her small changes in color may be the result of changes in her lighting.

Yes, thank you.
I do not think that is the problem.  We are both using SoLux 4700k, 36 degree, M16 bulbs in Juno fixtures for viewing.  Neither of us have a booth, but the area in my case is a neutral gray-white wall.  She says she is using the bulbs I sent her, but I do not know much about her viewing area.  I do think it is consistent because she says that she can hold the pictures up beside each other and see it.  That is why I think I want to be able to give her some numbers off targets with each batch.

Dave

[framah]

How about the possibility that the prints "age" somewhat over the  several months between printings.

Ask her to send you the prints that look different to her so you can see it also.  You might want to find someone who DOES see colors better than you to check them out.

I'd be willing to bet that 99% of the people viewing them side by side couldn't see what she is talking about  and  unless they are majorly different, you need to convince her that it isn't a problem anyone will ever notice.

Personally, I think she is seeing something that just isn't there.

[tgipson]

How about the possibility that the prints "age" somewhat over the  several months between printings.

Ask her to send you the prints that look different to her so you can see it also.  You might want to find someone who DOES see colors better than you to check them out.

I'd be willing to bet that 99% of the people viewing them side by side couldn't see what she is talking about  and  unless they are majorly different, you need to convince her that it isn't a problem anyone will ever notice.

Personally, I think she is seeing something that just isn't there.

I am very sympathetic with that situation. After years of comparison viewing of images with my wife who is a watercolor artist, I am now convinced that her perceptive color gamut is wider and more discriminating than mine. Though 99% of people may not see a difference, your artist may be one of the 1%. Good luck if that's the case. When I print images for her, I have to adjust the color to something different than I perceive as the "correct" color.

[Ernst Dinkla]

I am very sympathetic with that situation. After years of comparison viewing of images with my wife who is a watercolor artist, I am now convinced that her perceptive color gamut is wider and more discriminating than mine. Though 99% of people may not see a difference, your artist may be one of the 1%. Good luck if that's the case. When I print images for her, I have to adjust the color to something different than I perceive as the "correct" color.

It is possible that your wife has that special color sensitivity:

http://en.wikipedia.org/wiki/Tetrachromat



met vriendelijke groeten, Ernst Dinkla

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/

[bjanes]

It is possible that your wife has that special color sensitivity:

http://en.wikipedia.org/wiki/Tetrachromat

met vriendelijke groeten, Ernst Dinkla

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/

These tetrachromats may be more common than previously thought, and it is entirely possible that the standard CIE color matching function does not work for such people and accordingly color profiles based on these functions may not produce a color match. However, this does not explain why the color changes with time for this lady.

Bill Janes

[Sven W]

How about the possibility that the prints "age" somewhat over the  several months between printings.

I've seen some examples of drifting or color changes with Enhanced Matte, i.o.w: the OBA is fading quite rapidly. In 3-4 weeks
you can end up with a almost grey paper and that also effect the perception of the color, although the ink itself is stable.

[AndreG]

hi,
There is a product that insures that the viewing light is correct. It is a strip that you stick to the print. It is very expensive but it does work.

I can look it up in my files if you wish.

[Dave Carter]

Thanks all,
I think for now I am going to try the target idea.

Pratic, if the target idea doesn't work, I may ask you to look it you for me. Thanks, but don't bother yet.

[AndreG]

Hi,

Just in case, the strips are GATF/RHEM Light Indicator
The distributor is:

361 rue Isabey
St. Laurent, QC Canada H4T 1Y2
Tel 514.340.1103 Ext 223
Fax 514.340.1546
Toll Free 1.800.361.1035
http://www.treckhall.com

[Sven W]

Hi,

Just in case, the strips are GATF/RHEM Light Indicator

Well, the indicator just show you if there are metameric issues with the lightning condition. As colorguru Don Hutcheson puts it:

I strongly recommend eliminating any reference to the GATF Rehm
indicator. Contrary to GATF claims it does NOT indicate that lamps
are, or are not "5000K".
I recommend we do not include the Rehm indicator in the kit. Doing
so implies that it is adequate for approving lighting system, which it
is not.
FYI, the GATF Rehm indicator simply tests for one of many possible
metameric conditions. Just because it passes does not mean the light
is free from other metameric problems.
The Rehm indicator does NOT indicate the color temperature of a light
source.
The Rehm indicator does NOT indicate the CRI of a light source.

[Bob Peterson]

I need your advice on a printing problem.

...

My problem is she is VERY concerned about VERY small changes in color.  I always send test prints for approval before making the first batch.  And I also run a nozzle check on the printer before printing a batch.  After the first batch, she may order more several months later and sometimes complains that they are different even though I use the same paper and profile.  I keep one original batch print, but can not see the difference that she does.  Although, I have to say, I do not see some colors all that well.

...

Thanks for any advice.

Dave

Have you considered retaining a print from the first batch and, when you run a second batch later, comparing the print from the original batch to samples from the new batch?

You could send, as part of the second order, the original print, suitably and subtly marked.  Tell her what you've done and ask if she can identify the older print. Or you could ship 1/2 a print with the original order, and the second half with the reorder.  Her comparison of the two halves would tell the two of you if her environment is causing a (real or perceived) color shift.

Bob

[Dave Carter]

Yes - thanks Bob, very good points.  I think I am very close to your advice.

I have just sent a batch of prints which were all printed with my small target printed beside each one (example in first post).  I then measured the target values with EyeOne Share on a large sample of the prints and recorded the values. I have also kept several targets and prints as examples of this dates batch.

When I do another batch of this original, I will do the same thing and compare.  I believe I will have strong evidence as to any color shifts.

Thanks again,
Dave