Assertion: dye | /r/HasProperty | natural
Facets:
value: from plant sources
type: OTHER
value: at the time
type: TEMPORAL
Source sentences:
text: A dye can be natural, usually made from plant material such as berries, or artificial, meaning that it is made by humans from chemicals such as petrochemicals.
text: At the time, all dyes used for colouring cloth were natural substances, many of which were expensive and labour-intensive to extract—and many lacked stability, or fastness.
text: These may be natural (from plant sources) or synthetic.