Default Selection Brush 'expansion' behavior
By default the Smart Selection Brush Tool is set to intelligently expand the selection to include high contrast edges within the design, even if these are not directly painted.
The number of pixels selected is determined by the size (width) of the brush in two ways:
- A larger brush size will paint a larger area in one stroke and therefore more pixels are selected.
- A larger brush size will give Affinity Designer a larger sample size in which to determine how far the selection should expand.
Alternative 'non-expansion' behavior
As an alternative to the expansion method detailed above, the Selection Brush Tool also has a non-expansion method of selection. This method will only select pixels which are under the brush when the stroke is painted.
To create a pixel selection: