---
title: threshold
framework: pencilkit
role: symbol
role_heading: Instance Property
path: pencilkit/pkstrokepointreference/threshold
---

# threshold

The alpha threshold for clipping the stroke rendering for supported inks.

## Declaration

```swift
var threshold: CGFloat { get }
```

## Discussion

Discussion Only pixels with an alpha greater than the threshold are drawn. A threshold of 0 has no effect on rendering; a threshold of 1 draws nothing. Thresholds apply only to some inks, such as PKInkIdentifierReed.