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29 Mar 2011

RGB Printer Profiling with i1 Profiler








Over the past few months I’ve been one of the team beta testing the new X-Rite i1 Profiler software, and now that it’s been officially released I can begin a series of blogs taking you through the new software. We’ll start with RGB printer profiling, in my tests the new software produces profiles that are noticeably better in many areas than i1 Match, ProfileMaker or Monaco Profiler. Also for users of i1 Match the new software includes advanced functionality previous only available in ProfileMaker or Profiler, but before we delve into the RGB printer profiling workflow it’s worth saying a few things about the general interface.

The opening screen or page of the software has several useful features including the ability to automatically check for software updates, access information about the software online and most important of all access training videos. One of my standard pieces of support advice is RTFM - Read The Flippin’ Manual. I’m sorry, but having written software manuals in the past I’m one of those people that reads the supplied manual for whatever they buy, it usually saves me a lot of time and lets me find features that might remain hidden if I didn’t know they were there. However, I realise not everybody gets on well with software manuals, apart from maybe as a cure for insomnia, so what I suggest is that the first time you open i1 Profiler you have a cup of coffee to hand and sit back and watch the training videos supplied via the handy button on the screen. They cover most of the functions of the software and are clear and very easy to understand.

i1 Profiler has two modes, Basic and Advanced. The Advanced mode really comes into its own when you’re profiling CMYK printers and for a lot of users doing just RGB printer profiling using the Basic mode will just stop you being presented with options that you’d always leave to default anyway, but in the interest of full disclosure I’ll write the rest of the blog assuming you are going to use the Advanced mode.

i1 Profiler uses a a step by step process and the options for each page can be saved into a workflow. Default workflows are supplied but you can also save your own to suit your own kit or processes. A workflow can include options such as the number of patches, page size and profile settings. Saved workflows, previous profiles and other saved data can be dragged and dropped onto the buttons in a workflow to set the options.

The first page, Patch Set, in an RGB printer profiling workflow defines the number of patches you want to measure. You can measure as few as 400 or up to 6000. In my experience you get little benefit from measuring over 1000 patches for an RGB printer profile. You have the option of scrambling or randomizing the order of the patches just in case there is any difference across the sheet, but there shouldn’t be on a inkjet printer. Once you have selected the number of patches you can then move on to the next page, Test Chart.

The Test Chart page allows you to define what measuring instrument you are using, the page size of your printer and other physical options relating to how the chart is laid out. You might have to step back and forth between Patch Set and Test Chart until you find a number of patches that fit on a certain number of pages. Personally, I think it would be better if they combined the Patch Set and Test Chart pages so you could define the page size and instrument then click a button to fill the page with patches. Anyway, once you have define the parameters you can then print the target or save it as a TIFF file.

The Measurement page is obviously where you connect your measuring device and measure the colours, and pretty much does what it says in a similar way to other profiling software. The next page, Lighting, is a new option that will be unfamiliar to users of i1 Match. Printer profiles can be built based on an expected viewing light to help improve the accuracy of the profile under that lighting condition. For example, if you were producing prints for a gallery that had a particular type of lights you could measure those lights and then use that measurement data when the profile was created to make the prints look good under that light source. Usually, however, you don’t know where the print will be viewed so the best thing for the vast majority of users is to leave the lighting options set to the default of D50 and skip the Lighting page.

Profile Settings also allows a lot of control over areas that most users will leave to default. The perceptual mapping options allow you to increase or decrease Contrast or Saturation and also the Neutralize gray option allows you to choose if gray colours are mapped relative to the colour of the paper or more absolutely neutral. The effect of these options will only be visible when printing with the perceptual rendering intent and I’d recommend first building a profile with the default options (all to zero) before changing anything. The effects are subtle but can be quite pleasing. The Tables option govern the size of the tables within the profile, again there isn’t much need to deviate from the defaults. By the way the defaults are displayed as ‘Custom’ for some reason - one of the issues I reported back during testing they didn’t have time to fix. Advanced sets other options most users won’t touch, you can find out what any option means by activating the Help function by clicking on the question mark at the bottom left of the screen and putting the cursor over the item you want explained.

The final ICC Profile page lets you save the profile. A 3D gamut graph of the profile is then displayed. You should then go and test the profile by outputting a few files before trying the new profile optimization and verification options, but more about those in the next blog.

If you want to test the quality of the profiles from the new software then we’ve already swapped our custom profiling service (http://www.nativedigital.com/products/Custom-ICC-Printer-Profile.html) over to using the new software.

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