# `GSLayer previousKerning(to:direction:)`

*Instance Method*

Kerning value between a previous layer and this layer, or `nil` when no kerning value is defined.

## Declaration

```swift
func previousKerning(to previousLayer: GSLayer, direction: GSWritingDirection) -> CGFloat?
```

## See Also

### Kerning Values

- [`GSLayer.kerning`](/Core/GlyphsCore/GSLayer/kerning) — Kerning dictionary for observing kerning changes.
- [`GSLayer setPreviousKerning(_:to:direction:)`](/Core/GlyphsCore/GSLayer/setPreviousKerning(_:to:direction:)) — Sets the kerning value between a previous layer and this layer.
- [`GSLayer nextKerning(to:direction:)`](/Core/GlyphsCore/GSLayer/nextKerning(to:direction:)) — Kerning value between this layer and a next layer, or `nil` when no kerning value is defined.
- [`GSLayer setNextKerning(_:to:direction:)`](/Core/GlyphsCore/GSLayer/setNextKerning(_:to:direction:)) — Sets the kerning value between this layer and a next layer.