You can copy (clone) paint on region on your model and apply the paint to another area of the same model (and same paint layer) using the Clone tool.
Indicate a sample point on the area you want to clone and then move the cursor to the area you want the paint applied.
When you stroke on the model the paint is copied from the sample point (which updates as the Clone tool gets repositioned). If a composite of more than one paint layer is required, you can merge the paint layers before cloning. For more information, see Merge paint layers.
While many paint layers may be visible, only one can be active. The active layer is the one that Clone works in. If you don't want to risk editing an existing paint layer, create a duplicate of it prior to using Clone. For more information, see Duplicate a paint layer.
This location is the starting point from which the Clone tool copies the paint.
Paint is applied in the location you stroke in relation to the sample point. As you move the tool on the model the sample point updates to maintain the offset.