Propolis while also collecting water and tree resin necessary for the production of propolis. The chemical composition and nature of propolis depend on environmental conditions and harvested resources. For centuries, beekeepers assumed that bees sealed the beehive with propolis to protect the colony from the elements, such as rain and cold winter drafts. However, 20th century research revealed that bees not only survive, but also thrive, with increased ventilation during the winter months throughout most temperate regions of the world. Propolis properties may include: The composition of propolis varies from hive to hive, from district to district, and from season to
Rabbit-skin glue Rabbit-skin glue Rabbit-skin glue is a sizing that also acts as an adhesive. It is essentially refined rabbit collagen, and was originally used as an ingredient in traditional gesso. In traditional oil painting as practiced by the Renaissance painter, skin glue was used to coat the canvas. This is necessary because the linseed oil that forms the base of most oil paint contains linolenic acid that will destroy the canvas fibers over time. Though this did help to seal the canvas, they still had to cover it with another layer of a substance similar to paint in order to protect