What kind of thread do you use?
 

I read somewhere about the spools of thread and how they are wound on the spool. If the thread is stack wound you should have it on a vertical spool on the machine. If it is criss cross wound it should come off the horizional spool holder. Makes sense to me, but I wondered if anyone else has tried this.

no idea but as far as i know most cones are criscross wound and none of the machines ive seen have a place to hold those horizontaly.

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I just use whatever kind I have. It all works great for me.