Terpene tackifiers are natural tackifiers which are also referred as "universal" tackifiers due to their compatibility with majority of polymers. Terpene resins are especially compatible with polyolefins and the mid-block of styrene-isoprene-styrene (SIS) resins. Terpene tackifiers offer improved adhesion and their softening point is generally higher than others. Grades having high softening point provide excellent heat resistance. These resins also meet direct food contact requirements. Being naturally sourced, terpene tackifiers have a relatively high use but limited supply which leads to their higher prices.