A lig­a­ture is a char­ac­ter con­sist­ing of one or more con­nect­ing let­ters. As in the graph­ic above, sauer­stoff­flaschen—the Ger­man word for oxy­gen tank—is the only word to con­tain the “fffl” lig­a­ture. It also con­tains the dec­o­ra­tive “st” lig­a­ture. Below are exam­ples of stan­dard and dec­o­ra­tive lig­a­tures.

Let­ter pairs with their asso­ci­at­ed lig­a­tures in Adobe Caslon Pro

When appro­pri­ate, I always use lig­a­tures of well designed fonts for print and screen. Though, some­times it requires a his­to­ry les­son…

As many peo­ple aren’t famil­iar with lig­a­tures, their use is often sus­pect. The use of some lig­a­tures has become so rare that some folks view them as jar­ring, espe­cial­ly when edit­ing or cri­tiquing designs. Some stan­dard ligatures—letter pairs like fi fl ff—will pass by unno­ticed while oth­ers (st ct sk sti) may raise flags. Then it’s also pos­si­ble, when not in edit mode/mood, some skep­tics will pass over the more extrav­a­gant lig­a­tures unno­ticed.

Often, con­cerns with lig­a­tures are not unfound­ed. Lig­a­tures can’t be used for every­thing, so it’s pos­si­ble to go over­board with them. They can be used in body copy above cer­tain sizes, but rarely should they be used for titles. Let­ter com­bi­na­tions in lig­a­tures can’t be kerned, so titles using them often suf­fer from blown spac­ing.