Always start with a high-res file (300 DPI or higher) to avoid pixelation in halftones.
Despite its name, the Mantra Color Separation Script is not a standalone software. It is a file designed to run inside Adobe Photoshop . It was originally developed by a community expert known as "Mantra" to solve a simple problem: Photoshop does not natively handle simulated process color separation well.
Streamlining Screen Printing: A Guide to the Mantra Color Separation Script