Forest chalk
Under forestry chalk (also Forstsignierkreide or crayon ) means chalks, to weatherproof the, light-fast marking of dry and wet wood, but also stone, asphalt, metal, and other harsh materials are suitable. Its structure and manufacture correspond to the colored leads used in colored pencils . Also as crayons are wax crayons designated to be used in industry and trade for the labeling and marking on smooth surfaces.
Forest chalk, like blackboard chalk, consists of alabaster , a special type of gypsum (chemical calcium sulphate), to which, unlike blackboard chalk, oils or fats are added, whereby a certain weather and smear resistance is achieved with higher break resistance.
Forest chalk is usually made in hexagonal pencils with a length of 120 millimeters and a diameter of 8–12 millimeters. It can be sharpened with a pocket knife. To avoid staining the hands, forest chalk is wrapped in paper. Nowadays it is mostly used in clamp holders similar to mechanical pencils for loose leads, which also helps prevent breakage.
Commercially available colors are red, green, yellow, blue, black and white as well as fluorescent.
There is no DIN or ÖNORM standard .
literature
- Author collective (ed.): Merck's Warenlexikon . Leipzig, published by GA Gloeckner, 1884 (3)
Footnotes
Remarks
- ↑ Industrial chalks . (No longer available online.) Lyra.de, archived from the original on October 19, 2013 (illustrations of such clip holders called crayon pencils together with crayons in a supplier's catalog)
Individual evidence
- Jump up ↑ chalks - marking chalks. ( PDF (approx. 2.3 MB)) In: Faber-Castell - Consumer handbook. faber-castell.de, p. 33 , accessed on December 18, 2017 .
- ↑ Chalk markers. wolf-signiertechnik.de, accessed on December 18, 2017 .