Why a Colour Looks Right on Screen and Wrong in Print
A colour changes in print because the two systems build it in opposite directions. A screen emits red, green, and blue light and adds them together; a press lays down cyan, magenta, yellow, and black ink that subtracts light. Some screen colours have no ink equivalent at all, and those are the ones that shift.
That gamut gap is why a proof argument is rarely about anyone's mistake. The designer saw a colour the press cannot make, the press produced the nearest thing it could, and both parties are describing the same file accurately. What stays out of the published version is your own press condition: ICC profiles, ink limits, and the substrate combinations you run are commercial detail that changes by job and should stay in the quote rather than in a training module.
The template walks the file through seven scenes: one on additive against subtractive colour, one on gamut and which colours cannot survive conversion, two on the prepress checks that catch problems before plates, one on rich black and why it is the most common single fault, one on proofing and what a proof does and does not promise, and one on what to send.
