Must I calibrate?
I’m frequently asked "My prints already match my monitor. Do I really need to calibrate?"
The answer is "No you don’t, but yes you should."
Obviously, at this point in time, if your prints are turning out exactly as you expect, then there’s no immediate problem. Ultimately, the whole goal of colour-management is to get no nasty surprises when you open your packet of prints from the lab.
But one of the purposes of calibration is to standardise your screen’s output from now to the end of its useful life. This is the key issue here – screens change. Let’s face it, any electrical or electronic device changes over time. Your toaster won’t toast your bread as evenly after a couple of years as it did when you first bought it. So it is with screens.
If you don’t calibrate, the first time you’ll know that your screen has drifted is when you open that package of expensive useless prints from the lab. Nobody wants that cost or hassle!
The important thing I want to make clear is this: If your screen is already very good, calibrating it won’t make much, if any, visible difference. A large part of the process we call "calibration" is simply to record a description of the characteristics of your screen.
So we come back to the first point. If calibrating your screen tomorrow won’t change it, why bother? Because calibrating will ensure that your screen looks the same in three years as it does tomorrow. And that is peace of mind.