I use Mettler bobbin thread. Can someone tell me what is the difference between Metrolene and Seralene? The info on them are both 100% Polyester.

Mettler has changed the name of the Metrolene thread to Seralene. The Metrocor thread name has also been changed. It is now Seracor.

Good question. How do we compare threads to know what are the good ones and the ones that should be avoided? There are so many new brands coming out now.

I hope this helps you. Metrolene is a continuous 2 ply fine poly, the only thing I can find on the Seralene is that it is a monofiliment that is used for surgery. Sorry I can't help more.