To import your finished painting from Photos back to Brushes for Mac, you can follow these steps:
1. Open Brushes Viewer on your Mac.
2. Look for an "Import" or "Open" option within the program.
3. Navigate to the location where you saved your finished painting in Photos.
4. Select the painting file and click on import or open.
5. The painting should now be imported and ready for you to make any additions or modifications within Brushes Viewer.