The K242HQK has a maximum contrast ratio of 100000000:1. That's over twenty times the contrast ratio of a 5000000:1 flatpanel monitor, which is the most frequently found contrast ratio.
A 100000000:1 dynamic contrast ratio is actually the best contrast ratio amongst all medium monitors that have been available for around the same time as the K242HQK.
Amongst comparable types of PC screen the worst contrast ratio is Mega Contrast.
It may also be worth considering one of the alternative flatpanel monitors that have a 100000000:1 dynamic contrast ratio currently available including the G277HL ($127.99), or the G246HLF both from Acer which has a better Rating.