Assertion: ballpoint pen's ink | /r/ObjectUse | used in ballpoint pens
Facets:
Source sentences:
text: The ink used in ballpoint pens is oil based and dries faster than other types of ink.
text: The oil-based ink used in ballpoint pens is more permanent than water-based ink.
text: The ink used in ballpoint pens is oil based and was originally designed as a cleaner more reliable alternative to fountain pens.