Source: Schema.org v30.1 vocabulary. Official material property definition.
What does material mean?
A material that something is made from, e.g. leather, wool, cotton, paper.
Used on types (domainIncludes)
Expected value types (rangeIncludes)
Schema.org domainIncludes and rangeIncludes are descriptive guidance, not strict validation prohibitions. Check the official reference for updates.
Related reference
Browse all Schema.org types and properties · Google feature support status