Propolis propolis has approximately 50 constituents, primarily resins and vegetable balsams (50%), waxes (30%), essential oils (10%), and pollen (5%). Propolis also contains persistent lipophilic acaricides, a natural pesticide that deters mite infestations. In neotropical regions, in addition to a large variety of trees, bees may also gather resin from flowers in the genera "Clusia" and "Dalechampia", which are the only known plant genera that produce floral resins to attract pollinators. "Clusia" resin contains polyprenylated benzophenones. In some areas of Chile and Argentina Andean valleys, propolis contains viscidone, a terpene from "Baccharis" shrubs, and in Brazil and Paraguay, naphthoquinone epoxide has
Glue-size high perishability of linen cloth and the solubility of hide glue. Well-known and relatively well-preserved — though substantially damaged — the most notable examples include Quentin Matsys' "Virgin and Child with Saints Barbara and Catherine" (c. 1515-25) and Dirk Bouts' "Entombment" (c. 1440-55). In German the technique is known as "Tüchleinfarben", meaning “small cloth colours”, or "Tüchlein", derived from the German words "Tüch" and "Lein" ("fabric" and "flax"). A binding agent for pigment was made by boiling animal skin mixed with other organic tissue and applied to linen, itself prepared with a thin layer of glue. The linen was ground,