On Maundy Thursday during Holy Week between Palm Sunday and Easter the a bishop of Roman Catholic Church and some Protestant churches customarily consecrates the Holy Oils (Olea Sacra) for use in the diocese during the coming liturgical year during the chrism Mass.
In Apostolic times St. James directed the priests or elders of the community to pray for the sick man and to anoint him with oil in the name of Jesus (James, v, 14). The Oil of the Sick is blessed with that specific intention.
The oil of catechumens is the ointment of those preparing for baptism. It wards off what is evil. It brings wisdom and strength. This oil is also used in the ordination of priests and the coronation of kings and queens. The oil of catechumens is traditionally an olive oil, but any vegetable oil may be used.
A mixture of oil of olives and balsam and is used in the administration of the Sacraments of Baptism, Confirmation, and Holy Orders, in the consecration of churches, chalices, patens, altars, and altar-stones, and in the solemn blessing of bells and baptismal water.