Using ColorPort for QTR grayscale and alt-process profiling

ColorPort is free utility from XRite that allows users to make and measure profiling targets with a wide variety of spectrophotometers, including the versatile 1Pro. This software and hardware combination is the modern day equivalent to yesterdays densitometer that provides much more information and functionality. I've been using ColorPort on a daily basis since 2005 and love it's flexibility and versatility. If one is savvy enough to hack color patch spreadsheets and XML files, one can design beautiful targets for nearly any profiling purpose. I've preferred ColorPort over MeasureTool for years, but now that XRite has discontinued MeasureTool and the Mac OS will no longer launch it; color geeks everywhere are making the switch.

B&W inkjet printmakers and Quad Tone RIP (QTR) users in particular will love to hear that I’ve just made it easier than ever to ditch MeasureTool and start using ColorPort. Visit www.on-sight.com/downloads/ to download the 21 and 51 step gray ColorPort XML files that I’ve made for the i1Pro and iSis. These files can be installed at the following location:

Mac OS: [user folder]>Documents>ColorPortResources>refs>cmyk
Windows: C:Documents and SettingsAdministratorMy DocumentsColorPort_Resources
efscmyk\n
I’ve also made my Grayscale and Alt-Process profiling targets available with patches for the i1Pro, and iSis and DTP70 patches on separate layers that can be enabled. These profiling targets have large 21 step patches that come in handy with irregular alt processes and some images to help monitor the tonal scale during testing. The values of the 21 and 51 step targets are exactly the same as those from QTR. Feel free to use these targets for non-commercial purposes.

With the XML files installed, launch ColorPort, and choose the target you wish to measure. i1Pro users should then click on the circular “i” to the right of the measurement device, choose spot or strip reading (I prefer spot measurements), calibrate your device and begin measuring the target patches.

If you click on the circular “i” to the right of the measurement status, you’ll see a nice window that shows your measurements in a variety of modes. Some will appreciate the densitometric values while others might like the spectral visualization of each patch.

Colorport can display the densitometric values of your measurements as well as a spectral visualization. Click to see the full dialog.

Once your measurements are complete, click the “Save Data” button on the lower right. Choose “Tab Delimited” for the format, leave the conversion on XRGA, and make sure that the only checked boxes are “Lab” and “XYZ” with the Illuminant set to “D50” as pictured here. Save your measurement file.

Important Save As options. Click to see the full dialog.

You now have a measurement file that you can drag and drop onto the “QTR-Create-ICC” script to make an ICC Color Profile for your grayscale printing process! Of course, QTR users can also drag and drop this measurement file onto “QTR-Linearize-data” and use the linearization curve in QTR. Tip of the hat to Roy Harrington for his brilliant work on this script which is available for download at www.quadtonerip.com. Roy’s grayscale profiles can be used for soft proofing in Photoshop complete with hue and paper color simulation.

Softproofing with a QTR Grayscale profile displays the image with full color/hue and Dmax simulation

You can also use this profiling process to color manage Advanced B&W printing modes and alt-process negatives. More on this in another article soon.

If you choose to open up this measurement file in a text editor, the leftmost column of numbers contain the pertinent Luminosity channel numbers. If any of these numbers aren’t sequential QTR-Create-ICC won’t make a profile. If this occurs you probably have an anomaly in one of your measurements that you can manually fix in the text editor. I sometimes find a single patch in the shadows that is slightly out of sequential order, and adjusting this value so that QTR-Create-ICC can make a profile has no detrimental effects.

Measurement file with non-sequential value that should be corrected to 7.71

Of course, my clients that would rather not invest in a spectrophotometer and all this geek stuff can utilize my private remote profiling service. While I think most will want to do this themselves, it’s always good to have options. I hope this is useful – enjoy making grayscale profiles!

– Scott Martin

Update 4-26-12 XRite has upgraded ColorPort to version 2.0.5 to address some issues some users were experiencing and to support the new i1Pro2 device.