About: http://webisa.webdatacommons.org/56530362

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Tip 17 may be any suitable material such as graphite, charcoal, crayon, chalk, or porous felt as already previously indicated.
http://www.w3.org/ns/prov#wasQuotedFrom	patentgenius.com