Background Blur replicates the blurs behind overlays and panes in macOS and iOS. Content underneath your layer will blur and you can set that content’s saturation and a blur amount in the Inspector.
If you have any fill styles on this layer, they’ll need to be transparent in order to see this blur. A transparent color fill is also a great way to tint it.
Layer blur has three distinct blur styles: Uniform, Linear Progressive, and Radial Progressive. Each one provides a unique way to control how a blur applies to layers, making it possible to create nuanced and dynamic effects.
- Uniform Blur:
affects the entire layer. You can control the intensity of the blur using the slider, or the input field in the Inspector.
- Linear Progressive Blur:
also applies to the entire layer, but the degree of the blur increases (or decreases) gradually. You can adjust the direction using the canvas controls, and the blur amount by using the slider, or the input field in the Inspector.
- Radial Progressive Blur:
very similar to Linear Progressive, but in a radial/round shape. You can control the size of the blur with the canvas control.
To edit a layer’s linear or radial blur direction, select the layer and click on the sliders icon 
in the Inspector to display the stops on the canvas.
