A retablo is a two-dimensional painting of a saint or religious event. The Spanish word "retablo" means board behind, or behind the altar.  It is arte sagrada (sacred art) indigenous to Mexico and New Mexico Hispanic culture that speaks to and emerges from a spiritual way of life. Retablos of Catholic religious figures and biblical scenes first appeared after the Spanish conquest of Mexico. Used as household altars displayed individually or in groups, they became an important part of religious worship in the Americas.

In New Mexico the painting is usually done on ponderosa pine of various shapes and designs; while in Mexico, retablos are more frequently painted on tin. The wood board is first covered with gesso, which is a mixture of gypsum and/or marble dust with a binder of glue made from animal skins or vegetable gelatin. The paint medium includes powdered pigments from natural elements, such as minerals, rocks, flowers, insects, and clays, mixed with gum arabic to create water colors. Once painted, retablos are usually varnished with a mixture of pinon sap and grain alcohol.  After drying, a final coat of natural resin wax is applied to seal the image.  The iconography of the santos (saints) tells stories in very subtle ways, connecting the artist and the viewer in a divine symbolism. The borders, curtains, clouds and other devices used in retablos provide a devotional window into the divine, which are used to move the eye from the external world into the sacred world of the icon.