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,
Glue-size but sometimes treated, by both the glue and also white chalk, which allowed a surface suitable for underdrawing and a base that would not absorb the final layer's pigment. The advantage of using glue as a binder is that the colours render as matte and opaque textures suited to austere or mournful images as opposed to the translucent appearance associated with oil. Many reds and blues bound in glue would have appeared with a brilliance and intensity difficult to achieve with oil. Unfortunately the surviving examples have greatly deteriorated over time, having suffered from colour alteration due to exposure to