Scale Tool
From Synfig Studio :: Documentation
The scale tool works much like to Normal Tool except for when multiple ducks are selected. To see this, select multiple ducks, by either:
- pressing Control-A to select all ducks
- dragging a rectangle around a group of ducks
- holding the Control key while clicking ducks to toggle their selected status
Then drag one of the selected ducks. All the selected ducks will be scaled relative to the centre of the selected group.
The rotate tool has a tool option, 'Lock Aspect Ratio', which when selected will prevent you from changing the x:y ratio of the bounding box of the selected ducks.