Creat postscript (ps) file by using TexShop

1. Save all image files as *.ps
  - In Adobe Acrobat, File > Save as > More Options > Encapsulated ostScript(.eps).

2. In the TexShop preferences,
  - Check Tex+DVI in the Typesetting tab.
  - Check Save Postscript File in the Engine tab.
  - Click Typeset.