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QTR and PrintFIX PRO to get better black and white prints

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Using QTR and PrintFIX PRO to get better black and white prints

Greyscale ICC profiles to improve your black and white printing



Linearise your B&W printing. As well as very good black and white printing, Roy Harrington’s excellent QuadToneRIP package ($50 shareware) allows you to create luminance only icc printer profiles to linearise print output. Article looks at why you would use it and the benefits it can bring.

curves for printers

The process can work with any black and white printer output (including the specialist black and white printing modes on some newer printers).

This article is now several years old (the SP1290 is long gone), but the principles are still relevant. The process still works with the latest SpyderPrint device. We have similar newer articles about the same process with different hardware and software.
B/W and the ColorMunki
Using ColorPort and the i1Pro 2
i1Profiler and measuring for QTR

Better Black and White printing

The Spyder3Print SR is the latest profiling solution as of Summer 2009 – If you have a PrintFIX PRO then you can download the updated software (for free) from datacolor – We have reviews covering all of datacolor’s (aka ColorVision’s) profiling products (including their new monitor profiling solution the Spyder3Elite and Pro).

The profiling part of the software was written for use with an Eye-One Spectrophotometer. Keith has been looking at using the appreciably cheaper PrintFIX PRO (now SpyderPrint) to take the measurements you need to create these profiles.

The image is of Keith’s black and white test print. 

black and white test print imageIt was created to give a harsh but fair test of any B/W printing system. (download page)

BW profiles

In my review of PermaJet Monochrome Pro inksi n an Epson 1290, I found that the best quality results came from using QuadToneRIP for printing. It’s a great piece of software (only $50) and capable of very high quality black and white printing.

Also included in the software package is an application “QTR-Create-ICC” which allows you to create profiles. It use a set of measurements, made with an Eye-One spectrophotometer, on a set of grey test patches.

The resulting luminance only icc printer profile can be used to linearise the output of a black and white printing system. Note that you can apply these profiles to any black and white printer set-up, not just using QTR.

Why linearise?

If you print out a set of grey scale patches, going in 5% steps (like the left hand side of the test image above), you might reasonably expect each patch to be consistently darker as you go from 0% (white) to 100% (black).

What about 2% steps? — here the likelihood of an even progression of tones gets much less certain. Deviations from a steady progression from light to dark are known as non-linearity, and can affect many different areas of a black and white print.

It’s fairly easy to spot blocked up shadows, but unevenness (steps) in the mid tones may not be immediately obvious. It’s one of the reasons I developed my test image above (I’ve a page with more details and a download link [updated version 2014]). The grey ramp and circular patch will usually show up any serious problems.

What you need is a way of measuring the printed output and making corrections for errors. Some time ago I wrote an article about this, using a flat bed scanner to make measurements and create Photoshop curves to ‘fix’ poor printing. The principles involved have not really changed, but improved measuring equipment and software make the whole process somewhat easier. In fact you could use part of the QTR software to produce profiles from the ACV files produced by my original method.

Testing my HP K80

I’ve regularly used my office printer as a quick test for colour management systems and papers. It’s not even supported on my Mac, so if I can get good results with it, then it bodes well for people with better and newer printers. In this instance I’m using the HPIJS Gimp-print driver from Mac OSX.

If you download QTR you will find the appropriate test files in the Eye-One folder in the CurveDesign folder. If you’ve got an Eye-One, then the procedures are pretty straight forward — print the test patches, measure them, and process the data file with “QTR-Create-ICC”

What about using the PrintFIX PRO? Well, in the current version of its software you can make individual patch measurements and note them down in a file for processing.

The image below shows the measurement values (Lab values) – you access it from the preferences menu option.

making individual measurements with a PrintFIX PRO

Spot reading

You can either note down measurements or you could set up a dummy patch measurement file in the PrintFIX software and copy the Lab values from it.

Note — With PrintFIX PRO V2 (and later SpyderPrint) software you can directly output measurements in QTR format

The test ramp was printed on plain paper, using the ‘Normal Greyscale’ setting in the driver.

The “QTR-Create-ICC” program expects data in a certain format. I’ve created an empty tab delimited text file that you can use if need be, for holding your data. (download link (zipped file))

Note. It seems that “QTR-Create-ICC” is pretty open in the data formats it can accept. A tab (or space) delimited set of readings with L, A and B at the top would do. I used Excel since it is easy to cut and past blocks of numbers, and I used the Chart function to create some pretty graphs :-)

Here is a version, opened in Excel, showing the cells you need to insert your measurements into.

data file format

I printed the 21 step greyscale wedge onto plain paper and noticed a slight problem. The patch reading aperture is quite a bit larger with the PrintFIX PRO than the Eye-One, and I know from experience from testing, it is easy to get part of the edge of a patch — ruining the reading.

Easily fixed – rotate the paper to landscape in the page setup, and print at 150% size.

After letting the paper dry, I measured the patches and put the data into the file in the right format.

plain paper data

Notice that ‘L’ value for 45% — it’s out of step (as are some others)

Since I’ve used this printer for a lot of testing, this was not that much of a shock. However I knew that it might well stop any further tests in this instance.

The “QTR-Create-ICC” software has no interface, it just takes a data file and processes it. It either works or it doesn’t :-)

In the output screenshot below, the software has taken exception to Luminance (‘L’) values this uneven. The output graph shows a very uneven set of L values.

profile generation error message

This is the point where you give up with these driver settings!

I could have tried a better paper and different settings but really if it’s this bad, you are unlikely to be able to get good black and white prints without some serious settings changes.

The icc profiling I’m describing here, is really for fine tuning B/W printing … there is a limit to what you can do.

Using my Epson 1290

After the K80, I decided to try for good black and white with my Epson Stylus Photo 1290, which currently has colour Epson dye inks in it. I printed using black ink only, on some spare (unbranded) photo paper.

The measurements were much better this time, with a very good deep black.

measurements for profile generation

This time the software accepted the measurement file and created a luminance only icc profile.

Note the long name I’ve given it in the window below. All that stuff means something to me … even so, it’s good to write things down so it still makes sense in 6 months time.

After printing the greyscale ramp once more (using the same settings as before, but with the icc profile specified in the Photoshop printing dialogue) I took a second set of readings.

CS2 print dialogue - using bw icc profile

Printing with the new profile from within Photoshop CS2

Update 2012 – later versions of Photoshop on the Mac seem to dislike using profiles in this way with B&W print modes – see the QTR and ColorPort article for an alternate way of applying the profile to your printing.

The first graph below show the before and after sets of measurements (graph from data in an Excel spreadsheet)

profile before and after comparison

The red curve is much better, and in particular it was now possible to see the differences between 95% and 100% on the print.

The second graph shows up the ‘reversals’ in the K80 data

Note the different kind of errors in the two curves. The profile creation software can handle measurements like those for the 1290 (red) but not the K80.

Lastly, here is a view of what the profile contains (using the OSX ColorSync Utility)

icc profile contents

How good are the profiles

I printed my standard test print, and studied it carefully. Printing with the black ink only on an oldish printer like the 1290 is always going to show a noticeable dither pattern, but the tonal range was excellent.

Some of the very deepest shadow detail was still lost, but the overall tonality of the print was better than when I tried the same image on the same paper on an Epson R2400, using just the ‘Advanced B/W’ printing option.

Note for OSX 10.6 users – be sure to use the ‘QTR-Create-ICC-RGB’ application to create your profile. Ones created with ‘QTR-Create-ICC’ produce perfectly good profiles, but 10.6 does not see them…

Summary

A quick and easy way to improve the linearity of your black and white printing system.

When used with an already good setup like the ‘advanced B/W’ mode for newer Epson printers, the results are excellent.

You will need to make sure that your existing print setup is capable of moderate performance before proceeding, but if you look at the before and after curves in the ‘1290 Photo Paper’ graph above, you can see just how much correction can be applied.

More colour management and printing related information

For information about printers, paper reviews and profiling (colour management) see the Printing section of the main printers and printing page, or use the search box at the top of any page. All colour management information is indexed on the main Colour Management page.

Some specific articles that may be of interest:  

  • Why don't my prints match my screen? A short article showing why there is more to getting your prints to match your screen, than just calibrating your monitor. It's the vital first step, but you do need to consider some other factors for best results.
  • Why are my prints too dark - some basic suggestions to this common problem.

 


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