If you desire good colour management from your printer, you need to start with printer calibration. When we talk about printers, we mean inkjet, solvent, UV, toner or liquid ink-based print devices or print engines – basically, the vast majority of printing machines! Colour management 101 (our stock in trade) dictates that we should pay very close attention to printer calibration.

So – what is it, and why should you care?

Calibration is best described as the process of bringing a colour device (printer, scanner, monitor) into an optimal, quantifiable, repeatable state.

• Optimal: The best result obtained or obtainable under specific conditions.
• Quantifiable: Capable of being measured, which means it then should be…
• Repeatable!
  

Printer calibration could involve getting the printer could conform to an established industry standard (such as ISO 12647-2 for print) or a manufacturing standard/guideline or even your own specification.

Printer calibration enables you to keep track of “device drift”. Over time, even with consistent use of the same consumables (ink, toner, paper), your printer will suffer from device drift. We calibrate to make the printer behave consistently and bring it back into a repeatable state. This enables colour management to remain valid and accurate.

Printer calibration is best thought of as the first step of the colour management process. The second would be printer profiling or print ICC profiling.

Printer profiling is sometimes called characterisation – the process of recording a device’s behavior into a profile. It is simply a record or map of how the device produces colour – what it is capable of producing. This record (referred to as an ICC profile) will show you the device’s gamut (i.e. what colours it can and cannot print), reflected by the calibration process.

Printer calibration can be likened to having your car ‘dyno’ tuned for optimal performance.

Printer profiling can be likened to getting a report of your car’s ‘dyno’ tuned results – power output, torque, and so on.

Print calibration is like money in the bank – when you find your print colour has drifted, print re-calibration, back to the same targets, will enable your existing print ICC profile to be valid again – i.e. your colour will be back to where it should be!

How often should you re-calibrate? That can depend on your print device, and it is well worth taking the time to set up process controls to monitor and gauge device stability. Sometimes though, a certain amount of drift or instability may need to be accepted.

A small note: Some print devices cannot be calibrated – for example if the device is a non-Postscript printer and/or does not have a ‘RIP’ that usually includes some calibration tools. 

Colour Graphic Services can help you to do all this and more! Contact us to learn more about our cost-effective, stress-free solutions via our contact form

P
rinter calibration is required for any print device in order to get it into a stable, repeatable state.

Let’s break it down into what could be This is necessary as it enables you to bring the printer back in line, so to speak, as it will drift over time.the cause and what to check.

Basically, once you have the calibration process down pat you will be able to produce predictable, accurate and repeatable colour.

The idea is that if your colour starts to move away, out of tolerance, a quick check of the calibration, re-calibration or adjustment of the calibration will bring the colour back into ‘line’, without the need for complete re-profiling, etc…



For the wide format market, covering display, signage and the like, I am not going to be specific about the substrate or media, printer type, ink set and TIP type in use. There so many combinations it would take more than a month of blogs or more to cover…



Good colour management strategy dictates that you should always calibrate your device first before creating your ICC profile.

This is colour management 101!

Calibration – the process of bringing a colour device (i.e. monitor or display, printer, and even a scanner…) into an optimal, quantifiable, repeatable state. This condition could be an industry standard, manufacturers spec or guideline or your own specification.

With wide format printer calibration, the printer will be controlled by a RIP, and the RIP will usually have an in built calibration process prior to creating an ICC profile.

The steps of calibrating the printer will usually follow, but not always, this order:

1. Per channel ink limits
2. Linearisation (tonality)
3. Overprint ink limits
4. Grey Balance
5. Profile creation
6. Profile and colour management validation

Per channel ink limiting is usually the first step. This about achieving ink/media compatibility for each of the inks, per channel, C, M, Y and K. Too much ink being laid down can cause problems such as puddling, ink not drying, and ink reticulation.

To achieve the goal here, you are looking for the optimal result – enough ink without causing problems, together with enough ink to produce enough saturation larger than the target gamut you are aiming to simulate.

This step usually involves visual assessment and may include measurement using a densitometer or spectrophotometer.

This step usually involves visual assessment and may include measurement using a densitometer or spectrophotometer.

Tonality or tone distribution is about achieving smooth and even tone graduation from 0% to 100% for each primary channel C, M, Y and K. This step involves visual assessment and will include measurement using a densitometer or spectrophotometer.



Overprint ink limiting is about looking at the build-up of ink once the primaries (CMYK) are mixed together in different combinations – i.e. 100% M and 100% Y for RED. This step usually has a complex looking chart with rows of ink channel combinations in varying amounts.

This step definitely requires visual assessment.


Similar to per channel ink limiting except you are looking to find the step in each row that can produce the ‘best’ result with showing problems (ink puddling, not drying, etc.). You will probably need to input your results and print again to confirm your settings are correct…



Similar to per channel ink limiting except you are looking to find the step in each row that can produce the ‘best’ result with showing problems (ink puddling, not drying, etc.). You will probably need to input your results and print again to confirm your settings are correct…



I prefer to use a custom chart I have created for this purpose. It also helps you to decide on some important profile settings, such as total ink coverage and black start point. If the output of the calibration chart looks ok you can proceed to creating your ICC media/substrate profile.



Output your preferred CMYK profile chart – I like to use a profile chart with 2000+ patches for accuracy and coverage.

Measuring and building your profile really requires another blog as there are quite few options for measuring and then the settings for building your profile. Suffice to say once this step is complete you should be looking to validate your profile and validate your colour management settings in RIP, using your new media profile.

This does involve critical visual assessment, under the correct lighting (D50 – ISO 3664), and spectral measurement for reporting to see how your output now stacks up compared to an international print standard (ISO 12647) or an in-house standard. Again, I think it best to tackle this subject in a separate blog.

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