I know that this has been mentioned before in these forums, but I thought I should give it it's own topic since it's an amazing project and it is updating rapidly
ChromIQ is a free, open-source desktop app that builds custom ICC printer profiles — the colour "fingerprint" that tells your computer exactly how your printer, ink, and paper reproduce colour. With an accurate profile, what you see on screen is what comes out of the printer.
Under the hood it drives ArgyllCMS, the gold-standard open-source colour engine, through a friendly five-step wizard. ArgyllCMS does all the colour science; ChromIQ gives it a calm, guided interface so you never have to memorise a single flag.
What is new in 4.3: the Measurement Report with six report types, limit sets that include the published values of ISO 12647-7 and ISO 12647-8, evenness across the sheet, trend graphs and PDF reports; 190 built-in chart presets (154 in 4.2) with a gear button to choose which are listed; and ChromIQ complete in 14 languages, Ukrainian among them. The full list is in the release notes.
New to printer profiling? That's exactly who ChromIQ is for. Every screen has a clickable ⓘ icon that explains, in plain language, what the step does, what you need ready (device plugged in, paper loaded…), and what comes next. The in-app tooltips are the real manual — this README is the map.
https://github.com/itsab1989/ChromIQCurrently it supports the major more recent devices that Argyllcms supports:
i1Pro 1/2/3
Colormunki
Spectroscan
as well as the CHN Spec handheld Spectrophotometer, which can be found on aliexpress for about ~$70 USD
I recently added experimental support for the Konica Minolta FD-9 through an open source driver, and I've got a few other devices I'd like to attempt adding support for (like the DTP70, which was crippled long ago by lack of 64 bit OS drivers)
Also really impressive to me is that the dev, itsab1989 has built upon the argyll profiling engine to support multicolor (CMYK+N) profiling. If you haven't checked it out already, for a lot of people it could replace i1profiler or any other paid solutions. There's a lot of fun stuff happening when you turn on that "beta features" button in the prefs!
