There was no formal type of ship that was sailed by all pirates alike. This implies that there were no essential sail standards either. Oftentimes, pirates stole the ship they used so there was an opportunity factor involved. Depending on the era, pirates could have sailed anything from a brigantine or a caravel, to a galleon or a junk. By the 18th century, however, the best options were most likely to be schooners and sloops due to their maneuverability and speed.
Unlike privateers and naval captains, pirate captains were not bound to the same formal authority structures regarding repairs or alterations to their respective vessels. In this sense, pirate captains could generally opt for whatever alteration or improvement they desired or felt needed. When applied to sails, this meant building for speed. Not only did the ship need to be fast to accommodate the predatory raiding that typified many pirate vessels, but also to evade pursuing naval ships that were hunting them down while seeking to affect justice.
If many pirates opted for the sloop, we can see consistent features in the sails. This was a common vessel for pirates in both the Caribbean as well as the Atlantic. The jib topsail ran from the ship's boom upwards. Moving from the jib topsail toward the deck was the jib sail and then the staysail. The course rested at the rear of the main mast while the mast was topped by, perhaps naturally, the topsail. The main sail, also rigged to the mast, could be kept furled and then released when a particularly strong gust of wind needed to be captured. Many sloop-operating pirates chose to have bigger aft and fore mainsails as well as an enhanced bowsprit. The more sail they had, the faster the ship moved.
Ships of this period tended to have several decks. The war ships especially had multiple decks due to the need for cannon armaments. Sloops were designed with an aft deck, which pirates could remove. In this case, another jib, called the flying jib, could be added to the boom. This alteration allowed for more dynamic fighting on the open deck, as well as permitting more cannons to be stationed at the rear of the ship, thus improving the sloop's overall sense of balance on the water.