Copal is a name given to tree resin from the copal tree Protium copal (Burseraceae) that is particularly identified with the aromatic resins used by the cultures of pre-Columbian Mesoamerica as ceremonially burned incense and other purposes. More generally, the term copal describes resinous substances in an intermediate stage of polymerization and hardening between "gummier" resins and amber. The word copal is derived from the Nahuatl language word copalli, meaning "incense".
To the pre-Columbian Maya and contemporary Maya peoples it is known in the various Mayan languages as pom (or a close variation thereof), although the word itself has been demonstrated to be a loanword to Mayan from Mixe–Zoquean languages.
Copal is still used by a number of indigenous peoples of Mexico and Central America as an incense, during sweat lodge ceremonies and Sacred Mushroom ceremonies. It is available in different forms. The hard, amber-like yellow copal is a less expensive version. The white copal, a hard, milky, sticky substance, is a more expensive version of the same resin.
Copal resin from Hymenaea verrucosa is also found in East Africa and is used in incense. By the 18th century, Europeans found it to be a valuable ingredient in making a good wood varnish. It became widely used in the manufacture of furniture and carriages. It was also sometimes used as a picture varnish. By the late 19th and early 20th century varnish manufacturers in England and America were using it on train carriages, greatly swelling its demand.