Editing Slate (writing) (section)

== {{anchor|Slate pencil}}Usage ==

The writing slate consisted of a piece of slate, typically either 4x6 inches or 7x10 inches, encased in a wooden frame.<ref>"Standard Sizes of Blackboard Slate", U.S Department of Commerce: National Bureau of Standards (1966), 3.</ref> Split slate was prepared by scraping with a steel edge, grinding with a flat stone and, finally, polishing with a mix of slate powder in water. Pencils were of a softer stone, such as [[shale]], [[chalk]] or [[soapstone]].<ref>{{cite book |last1=Gwyn |first1=David |title=Welsh slate: archaeology and history of an industry |date=2015 |publisher=[[Royal Commission on the Ancient and Historical Monuments of Wales]] |location=Aberystwyth |isbn=978-1-871184-5-56 |page=45}}</ref> In 1853 [[Charles Goodyear]] patented a compound of [[vulcanised rubber|hard-vulcanised rubber]] with powdered [[porcelain]], from which to make white pencils for writing on slates.<ref>{{cite book |title=Specifications relating to India Rubber (Caoutchouc) and Gutta Percha, including air, fire, and water proofing |date=1859 |publisher=[[Eyre & Spottiswoode]] |location=London |page=343}}</ref>

Usually, a piece of cloth or slate sponge, sometimes attached with a string to the bottom of the writing slate, was used to erase it for reuse.