How do you use opacity in Paint.net?

To adjust the opacity of a layer in Paint.net, follow these steps:

1. Select the Layer: Highlight the specific layer you want to modify in the Layers Window. This selected layer is also known as the Active Layer.
2. Open Layer Properties: Press the F4 key. This action will open the Layer Properties dialog box.
3. Adjust Opacity: In the Layer Properties window, you'll find the Opacity setting (sometimes referred to as Alpha). The opacity value ranges from 0 to 255:
   • 0: The layer is completely transparent (invisible).
   • 255: The layer is completely opaque (fully visible).
4. Set the value: Adjust the value either by typing it or by using the provided slider.