Propolis Propolis Propolis or bee glue is a resinous mixture that honey bees produce by mixing saliva and beeswax with exudate gathered from tree buds, sap flows, or other botanical sources. It is used as a sealant for unwanted open spaces in the hive. Propolis is used for small gaps (approximately or less), while larger spaces are usually filled with beeswax. Its color varies depending on its botanical source, with dark brown as the most common. Propolis is sticky at and above , while at lower temperatures, it becomes hard and brittle. While foraging, worker bees primarily harvest pollen and nectar,
Animal glue The advent of synthetic adhesives heralded the collapse of the animal glue industry. Today, animal glues are sparsely industrialized, but still used for making and restoring objects, paintings, illuminated parchment manuscripts, and other artifacts. Gelatin, a form of animal glue, is found in many contemporary products, such as gelatin desserts, marshmallows, and pharmaceutical capsules, and is used to reinforce sinew wrappings, wood, leather, bark, and paper. Hide glue is also preferred by many luthiers over synthetic glues for its reversibility, creep-resistance and tendency to pull joints closed as it cures. This adhesive is mostly used as glue, sizing, or varnish,