PhotoPrint









Profiling Service

I can offer a basic and inexpensive colour profiling service to users of PhotoPrint / Gutenprint.  Currently, I'm making a token charge of 10 UKP, or 15 USD to cover my time.  I also ask that you tell me the make and model of your printer, the inks and paper you're using, and if you're using PhotoPrint, the appropriate .preset file.  These will be added to the database on the Profiles page.

This Profiling Kit contains two test images.  The first of these you will use to perform a rough linearisation on your printer; the second you will print out and post to me.


Choosing Appropriate Printer Settings:
These instructions assume you're usinng PhotoPrint, but the basic principle applies to the GIMP print plugin and even the CUPS printer properties too.
  • In "Printer Setup", choose an appropriate print mode and paper type.  If you need to make adjustments to the density, then you'll need to set the Print Quality to "Manual Control", and choose an appropriate resolution.
  • On the "Colour (General)" tab, set the Image Type to  "Manual Control".
  • On the newly-available "Colour (Fine-tuning)" tab, set Color Correction to "None".
  • The "Colour (Fine-tuning)" tab contains several other settings that will prove useful if the Density Check pattern highlights any problems...
  • Make sure that any existing colour management  is disabled.  In PhotoPrint's main window, select "Options -> Colour Management",  and uncheck the Printer Profile, if it's selected.  Finally, make sure the Default Colour  Space is set to "RGB".


Using the Density Check pattern:
Density CardThe Density Check pattern is designed to allow you to check the following four criteria:
  1. That the amount of ink deposited on the page is correct.  The darkest square in each "sweep" should  be just visible against the solid background.   It's normal for the Cyan, Magenta and Yellow squares to be more visible than the others.
  2. That the image gamma is about right.  If you peer through half-closed eyes at each sweep, you can judge where the stippled pattern matches the solid squares.  This should be round about the fifth or sixth square from the right hand side - in other words, slightly more than half-way across the strip.   (This isn't too critical, because the profile will compensate for this if necessary.)
  3. That greys are reasonably neutral.  The balance controls in PhotoPrint's print setup can be used to fine tune these if they're way out.   As long as the greys aren't too ill-behaved the profile will correct them.
  4. That there is no significant ink "bleeding" between contrasting dark areas.  If there is visible ink bleeding in  the bottom RGB test patches, then reduce the density until it stops.

Printing the Profiling Target:

Standard Profiling TargetThis target must be printed in RGB mode, with all existing colour management disabled.  The size must be no smaller than 6"x4" - making it larger is helpful...

Make a note of the setttings used to print this target, because the resulting profile will only be valid with those settings!

(Note that you can - and may want to - adjust  the "Composite Gamma" setting to compensate for viewing conditions - for instance, if you're using your monitor in a darkened room, you'll probably need to increase the gamma somewhat to achieve a perceptual match...)

Sending me your Profiling Target:
Once you've printed out your target, email me at blackfive@fakenhamweb.co.uk to let me know it's coming, then post to it me at:
Alastair M. Robinson
The Old Wesleyan Chapel
The Street, Syderstone
Kings Lynn
Norfolk PE31 8SD
United Kingdom

If you're paying me in UK pounds, then you can enclose your payment (either disguised cash, or cheque payable to A M Robinson). Alternatively, and if you're paying in US Dollars, you can pay me via PayPal - send your payment to blackfive@fakenhamweb.co.uk