Save custom particle effects to the Library
After you create a particle system, you can save it as a particle preset in the Particle Emitters, Favorites, or Favorites Menu folder in the Library, for future use. When you place particle systems in the Library, they become particle presets that can be used like any other particle preset.
Tip: For organizational purposes, create a folder of your own in the Favorites or Favorites Menu category to store custom particle systems.
Save a particle system to the Library
Open the Library and select the Particle Emitters, Favorites, or Favorites Menu category.
Drag the emitter you want to save from the Layers list into the stack at the bottom of the Library.
The customized emitter is saved in the /Users/username/Library/Application Support/Motion/Library/ folder (in the Particle Emitters, Favorites, or Favorites Menu subfolder). Any custom layers created in Motion (such as a shape layer) that you used to create that particle system are included in the file.