ICC PROFILES explained….
by Bill Owen – Lead Color Specialist at Alder Color Solutions
There are several types of ICC profiles depending on the kind of equipment that you wish to characterize. We will use input profiles for capture devices such as scanners and cameras. Monitor profiles that will allow the colors in your files to be displayed correctly on a calibrated screen. And finally output profiles, corresponding to the working space of the printing system. Different printing systems use different working spaces. For instance RGB profiles are used for photographic printing systems (such as Durst Lambda, Fuji Frontier) and inkjet printers running on native drivers supplied by their manufacturers. CMYK profiles are used with proofing systems and offset presses as well as digital presses.
Creating Input Profiles
To create input ICC profiles, specific charts are needed with known values. One of the most common charts is the “IT8 (Q60)” for scanners and the “ColorChecker” chart for cameras. The right piece of software allows the values seen by your scanner or camera to be compared to the target or reference values as it should have seen them. By capturing the actual values from the chart, ICC profiles can be created to automatically correct for inaccuracies in your particular camera or scanner characteristics. For digital cameras DNG profiles are most often used, especially for Adobe applications.
Creating Printer Profiles aka Output / Destination Profiles
To create an output profile, a chart like an IT8.7.3-7.4 or TC1617 (which will be IT8.7.5) or a custom generated chart must be printed with your system and read using a measuring device called a spectrophotometer. The profiling software compares the values in the original file to the ones measured on the printed document and creates a translation table which allows you to find out what value is required to produce accurate color for each color in your documents when printing to a specific device. This ICC Profile defines the white point, black point and achievable gamut of the device based on the ink and substrate used. It’s basically a digital fingerprint of a specific printer, ink and substrate combination. The image below is an example of a spectrophotometer made by xrite. It’s the i1Pro2 with the i1iO2 Table. The i1Pro2 can also work independently as a hand held device. We are now selling the newer recently released xrite i1Pro3, i1Pro3+ (larger aperture) and i1iO3 Tables as well.
Creating Monitor Profiles
The computer screen must both be calibrated and characterized in the same operation. To do so you need calibration software and a colorimeter or spectrophotometer, that allows the measurements to be taken on the surface of the monitor. Newer professional graphics displays allow you to calibrate automatically using the automatic display controls (ADC) while the software adjusts the screen settings (color, brightness, contrast). Measurements made by the spectrophotometer from the now calibrated screen are finally used to generate an ICC profile of the monitor. This profile is then loaded into your operating system and a lookup table is saved to your display internally which is loaded upon startup automatically and used to display calibrated colors correctly on screen. It is not required to plug this profile into graphic design applications. The image below shows the xrite i1Pro2 being used to calibrate a monitor.
Not only do we sell the products to do this, but we offer this as a service as well. We can build custom ICC Profiles for you and install them into your workflow.
For more detailed information on calibrating printing equipment,
contact Alder Color Solutions today at 877-753-8061 ! We provide both onsite and remote training.