Kern­ing is the ad­just­ment of spe­cific pairs of let­ters to im­prove spac­ing and fit. (It’s dis­tinct from let­terspac­ing, which af­fects all pairs.) Most fonts come with hun­dreds and some­times thou­sands of kern­ing pairs in­serted by the font designer.

Be­low, no­tice how kern­ing re­duces the large gaps be­tween cer­tain let­ter pairs, mak­ing them con­sis­tent with the rest of the font.

Al­ways use kern­ing. By de­fault, kern­ing is not ac­ti­vated in Word or Word­Per­fect, so you have to turn it on your­self. If you use para­graph and char­ac­ter styles, turn on kern­ing as part of your style definitions.