If you've created a layer that you want to use again, use Duplicate.
Duplicate will always apply to the entire layer, it cannot be limited by an active selection. If you want to only duplicate a piece of a layer, use copy and paste instead.
Duplicating a layer in Sketchbook Pro for desktop
- Select the layer and tap-hold
and sweep up and left to 
.
- or tap
and select Duplicate.
and sweep up and left to 
.
and select Duplicate.
Duplicating a layer in Sketchbook for mobile devices
Sketchbook on mobile devices does not have the duplicate layer function. Use copy and paste instead.
