# `GSGlyphEditView.interpolationLayerId`

*Instance Property*

While an interpolation preview is shown, the layer ID of the key layer whose design space location the preview has most recently passed over.

## Declaration

```swift
var interpolationLayerId: String? { get set }
```

```objc
@property (nonatomic, copy) NSString * interpolationLayerId;
```

```python
interpolationLayerId() -> str
setInterpolationLayerId_(interpolationLayerId: str)
```