# `PartState.material`

> Contract 2.0.0 · package sha256 `a857eca95b35921109faf997094bb4192f12527d9d0fcd4be7e97f06425bad6e` · generated from `configurator-runtime.d.ts` by `services/onsite-scripter/scripts/build-contract-docs.mjs`; edit the source, not this file.

Property of [`PartState`](PartState.md) · stable · since 2.0.0

```ts
material?: MaterialInput | MaterialPatch | null;
```

A MaterialSpec, however complete, merges field by field (RFC 7396) over what the part wears,
and a field set to null (a [`MaterialPatch`](MaterialPatch.md)) removes your value of it in this rule (spec
section 6.10, R5);
a Material or `{ materialNodeId }` replaces it, so a whole look is a Material from
[`materials.create(spec)`](Materials.create.md), crossfading with `fadeMs`. A URL-less texture in it changes only
placement and sampling of the texture the slot shows now, so a later [`select()`](Writer.select.md) or undo still changes the image.
Not for: a priced, saved choice, which is [`select(group, material)`](Writer.select.md).

**Default:** unchanged

## Generic-API test (spec 3.1)

| Rule | Result |
| --- | --- |
| 1. Neutral name | pass: `material` names no product |
| 2. A precedent | not recorded: no ledger row (coverage.json) names this member or its owner |
| 3. Two apps, or labs | pass: 19 apps (fleet cross-check: app-04c2774145, app-0c773a4ee3, app-37356bf09f, app-4762caacdc, app-4f16d2f6da, app-59c5b5751e, app-822bb9d6aa, app-8675b3225c and 11 more) |
| 4. The cheaper fix first | not recorded per member (Appendix B decides it per need) |