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Here's my take: if you calibrate and profile your monitor and then walk away, you're not done. You've done the work, but you haven't checked it.

Most of the people I talk to already know how to calibrate and profile a display. They hang the instrument on the screen, pick their white point and luminance, let the software run through its patches, and save the profile. That's a good habit. What a lot of people don't realize is that there's one more step sitting right there in the software, and it's the step that actually tells you whether what you see on screen is accurate. That step is checking conformance.

i1Profiler results screen after calibrating and profiling a display, showing white point and luminance on target
Where most people stop: i1Profiler's results after calibrating and profiling. White point and luminance landed on target, but this screen doesn't tell you how accurately the display shows color.

1. What conformance actually means

Conformance is checking your accuracy in a non-subjective way against a known reference. You'll hear that reference called a lot of different things: a standard, a specification, a target. For our purposes, they're all essentially the same idea. It's the thing you're trying to hit, written down in numbers.

The key word is non-subjective. "It looks good to me" is not conformance. Your eyes adapt, your room lighting changes, and everybody's sense of "good" is a little different. Conformance takes opinion out of it. You measure, you compare to the target, and you get a number that tells you how close you are.

On a monitor, that means displaying a set of known color values, measuring what the screen actually produces, and comparing the two. The gap between them is expressed as a color difference, usually Delta E (ΔE). Small numbers mean your screen is showing you what it's supposed to. Big numbers mean it isn't.

2. Calibrate, profile, verify

It helps to separate the three steps, because people tend to lump them together.

  1. Calibrate. You adjust the display to your target settings, things like white point, luminance, and tone response. This puts the monitor into a known, repeatable state.
  2. Profile. You measure how the calibrated display behaves and build an ICC profile that describes it, so your color-managed applications can show color correctly.
  3. Verify. You measure a set of colors through that profile and compare the results to the reference. This is the conformance check.

Steps one and two set things up. Step three tells you whether it worked. Skipping it is like setting up a press to a target and never pulling a sheet to measure it.

3. Running Display QA in i1Profiler

I'm going to use X-Rite's i1Profiler as the example, because it's arguably the most widely used monitor calibration software out there. Other packages have similar tools, and the idea is the same.

Once you've finished calibrating and profiling to your target settings, look for the small Display QA link. It's easy to miss, and that's exactly why so many people never click it. Click it. This is where conformance happens.

X-Rite describes the Display QA reference as a set of target color values used to confirm both the accuracy and the repeatability of your display. In other words, it's your reference, your standard, your target. The first thing i1Profiler asks you to do is choose a patch set, and that choice matters more than people think.

Patch set What it tells you When I'd use it
ColorChecker Classic (24 patches) General accuracy across a range of everyday colors Routine checks on any display; a good baseline
Spot or image patch set How well the display reproduces specific colors you care about Brand colors, spot colors, or colors from a specific job
Standard patch set + Industry Standard Target How accurately the display reproduces a printing or proofing specification Soft proofing, when the screen has to match a print standard

For the print and proofing option, you pick the industry-standard print specification that matches your workflow. This is the one I'd point most of our readers in printing and packaging toward, because it checks the display against the same kind of reference your press and proofs are held to.

4. Reading the results

After i1Profiler measures the patches, you get a QA report with a pass or fail. That pass or fail comes from two numbers compared against tolerances you set: the average ΔE across all patches, and the maximum ΔE, which is your single worst patch. If either one is over tolerance, the display fails.

Don't stop at the pass/fail, though. Look at the whole report. A few things I'd keep in mind:

  • Your patch set changes the answer. X-Rite points out that a display can pass with the ColorChecker set and fail with printer-oriented charts like IDEAlliance, IT8.7/3, or IT8.7/4. Those charts were built for printer profiling, and some of their patches sit outside what even very good monitors can show.
  • One bad patch can sink the max. A single out-of-gamut patch can fail the maximum ΔE even when the average looks great. Find that patch in the report and ask whether it's a color you actually need to reproduce.
  • Look at the lowest 90%. X-Rite suggests the average ΔE of the lowest 90% of patches as a good read on the display's real performance, since it sets aside the worst outliers.
  • Ambient light control raises the numbers. If you built your profile with Ambient Light Smart Control turned on, X-Rite says to expect higher ΔE values in Display QA.

If it fails, don't panic. Check that the display warmed up before you measured, that the instrument was sitting flat on the screen, and that your target settings are realistic for that monitor. Then recalibrate, re-profile, and run QA again.

5. Make it part of the routine

Conformance isn't a one-time thing. Displays drift as they age, and the only way to know how much is to keep measuring against the same reference. Run Display QA right after every calibration, and use the same patch set and tolerances each time so your results are comparable from one month to the next. Save the reports. Over time, they tell you how stable your display really is.

So here's my ask: next time you calibrate and profile, don't close i1Profiler when the profile saves. Click Display QA, pick the patch set that matches how you actually use that screen, and see how close you are to the target. That's the difference between thinking your monitor is accurate and knowing it.

Getting Started

If you want to know whether your displays are accurate enough for soft proofing, Alder Color Solutions can help you set up calibration, profiling, and Display QA, and interpret the results.
dang@aldertech.com

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About the Author

Dan Gillespie, Director of Technical Services at Alder Color Solutions

Dan Gillespie

Director of Technical Services, Alder Color Solutions

Dan has spent more than three decades helping printers, converters, publishers, packaging companies and photographers get control of their color, across offset, flexo, wide-format, digital and packaging production. He founded the color consultancy ColorGeek Inc. in 1999 and joined Alder in 2018.

A certified G7 Expert since the inaugural 2006 class, he has spent nearly twenty years implementing G7 and international print standards in real production environments, and was one of the few certified instructors for the SGIA Digital Color Professional program. He's also a professional photographer, which keeps him fluent in both the artistic and the technical sides of imaging.

Questions? Contact Dan at Alder Color Solutions: Email: dang@aldertech.com