RSS/Atom feed Twitter
Site is read-only, email is disabled

Gimp Printouts

This discussion is connected to the gimp-user-list.gnome.org mailing list which is provided by the GIMP developers and not related to gimpusers.com.

This is a read-only list on gimpusers.com so this discussion thread is read-only, too.

5 of 5 messages available
Toggle history

Please log in to manage your subscriptions.

Gimp Printouts cypher000 02 Apr 18:40
  Gimp Printouts Olivier Lecarme 02 Apr 18:50
  Gimp Printouts Jay Smith 02 Apr 18:54
  Gimp Printouts Hedley Finger 03 Apr 01:12
  Gimp Printouts Chris Mohler 03 Apr 01:18
2009-04-02 18:40:25 UTC (almost 16 years ago)
postings
1

Gimp Printouts

Hi there. Thanks for allowing me to join this forum. I have been using Gimp for some time, but now that I have got as far as printing out some of my work I have come across a snag.
I could not understand why the print was so much darker than the image on the monitor. Having scanned the help files in Gimp, I find the information, that this is because the monitor is showing the image in RGB,but the actual printout is in CMYK.
I am wrestling with the logic of this and failing to comprehend why it should be. I am hoping that there is a way of resolving this tremendous mis-match. Is there any Gimp knowledgeable member out there who could fill me in on the way to overcome this difference? I sure hope so. Many thanks. cypher000

Olivier Lecarme
2009-04-02 18:50:45 UTC (almost 16 years ago)

Gimp Printouts

Walter S. wrote:

Hi there. Thanks for allowing me to join this forum. I have been using Gimp for some time, but now that I have got as far as printing out some of my work I have come across a snag.
I could not understand why the print was so much darker than the image on the monitor. Having scanned the help files in Gimp, I find the information, that this is because the monitor is showing the image in RGB,but the actual printout is in CMYK.
I am wrestling with the logic of this and failing to comprehend why it should be. I am hoping that there is a way of resolving this tremendous mis-match. Is there any Gimp knowledgeable member out there who could fill me in on the way to overcome this difference? I sure hope so. Many thanks. cypher000

Please first mention what version of GIMP you are using, and on what platform. Mentioning the printer brand and model would be useful too.

On GNU/Linux or Mac OS, Gutenprint does a very fine job for printing.

Anyway, any printing software manages itself the conversion from RGB to CMYK. However, they need some information, in the form of ICC profiles.

Jay Smith
2009-04-02 18:54:21 UTC (almost 16 years ago)

Gimp Printouts

Walter,

There are multiple issues involved. For example:

- Since you did not mention anything about calibration, consider that the scanner, the monitor, and the printer are three different devices, each of which has to be properly calibrated (starting at the beginning with the scanner, then the monitor, and then the printer) using known source colors. This is the bane of "color work". The subject is enormous and has very little to do with Gimp itself.

The process of calibration can result in the creation of ICC color profiles which each piece of hardware uses (or I should say the programs on your computer uses when talking to each piece of hardware) to adjust for the color variations of the respective hardware.

- The printer, even when properly calibrated, is subject to all sorts of variations including temperature and humidity -- to say nothing of the paper -- at any given moment. We had a big color printer that we had to calibrate every few hours of operation.

- What you get from the scanner will vary over the life of the scanner. As it gets older, you will see changes in the color that it puts out. Thus it needs to be recalibrated from time to time.

- What you see -- or think you see -- on the monitor, even when properly calibrated, will vary greatly just be changing the lighting in the room where you use the monitor.

- The RGB to CMYK conversion depends greatly on many issues, including where the conversion occurs (in image and/or color management software on your computer, in the printer driver software, or in software resident on the printer itself.

The subject is huge and always gives me an enormous headache. I suggest Googling on color calibration and such subjects for more useful information that you can apply to your environment.

Keep in mind that what you have been seeing/editing/tweaking on your monitor may actually not be reality. I have five "identical" monitor (same brand and model), all configured the same way, but without any specific calibration to a color target. All five of them show the same image a little differently -- but one of them is massively different (whites come out very yellowish); that one needs to be repaired.

Good luck.

Jay

On 04/02/2009 12:40 PM, Walter S. wrote:

Hi there. Thanks for allowing me to join this forum. I have been using Gimp for some time, but now that I have got as far as printing out some of my work I have come across a snag.
I could not understand why the print was so much darker than the image on the monitor. Having scanned the help files in Gimp, I find the information, that this is because the monitor is showing the image in RGB,but the actual printout is in CMYK.
I am wrestling with the logic of this and failing to comprehend why it should be. I am hoping that there is a way of resolving this tremendous mis-match. Is there any Gimp knowledgeable member out there who could fill me in on the way to overcome this difference? I sure hope so. Many thanks. cypher000

Hedley Finger
2009-04-03 01:12:22 UTC (almost 16 years ago)

Gimp Printouts

Walter S. wrote:

I could not understand why the print was so much darker than the image on the monitor. Having scanned the help files in Gimp, I find the information, that this is because the monitor is showing the image in RGB,but the actual printout is in CMYK.
I am wrestling with the logic of this and failing to comprehend why it should be. I am hoping that there is a way of resolving this tremendous mis-match.

The monitor is a source of light and has a contrast ratio between pure white and black of 200:1 or so. A printed page can only reflect light that is falling on it and has a contrast ratio of about 30:1. Various papers also absorb the inks, so the filtering effect of the ink is not as great as it could be. Also, a rich black (CMYK overprinted) does not absorb all light that falls on it but actually reflects some so it more like a very dark grey. (If you turn all the lights in the room off late at night you will see that black on the monitor is not quite pure black, because some light is still being emitted from 'black' parts of the image.)

So your prints will always look duller than on the monitor. This is only apparent to you because you can compare the monitor with paper. Photos in magazines look okay to us because we are in no position to compare them with the original scene, film transparency, or digital photo from which they originated.

Regards, Hedley

--

Hedley Finger

28 Regent Street Camberwell VIC 3124 Australia Tel: +61 3 9809 1229 Fax: (call phone first) Mobile (cell): +61 412 461 558 Skype: hedley.finger Email. "Hedley Finger"

Chris Mohler
2009-04-03 01:18:26 UTC (almost 16 years ago)

Gimp Printouts

On Thu, Apr 2, 2009 at 11:40 AM, Walter S. wrote:

Hi there. Thanks for allowing me to join this forum. I have been using Gimp for some time, but now that I have got as far as printing out some of my work I have come across a snag.
I could not understand why the print was so much darker than the image on the monitor. Having scanned the help files in Gimp, I find the information, that this is because the monitor is showing the image in RGB,but the actual printout is in CMYK.
I am wrestling with the logic of this and failing to comprehend why it should be. I am hoping that there is a way of resolving this tremendous mis-match. Is there any Gimp knowledgeable member out there who could fill me in on the way to overcome this difference? I sure hope so. Many thanks. cypher000

Try preparing the image in GIMP, then printing from GIMP and also another program - compare the results.

There are issues with RGB->CMYK conversion in any program, but this test will at least let you know if GIMP's print plug-in is to blame for skewing the colors, or if you've just chosen colors that are out of gamut.

Chris