That mythical wrong twist thread
 

Found some. What a pain in the neck!!! It's a DMC metallic embroidery thread on a spool. It's three strands twisted together. You'd think since it's on a nice spool it would be for use on a machine. You'd think. It says on the back of the card "hand embroidery only." Mmmm, okay. How hard could it be to use on the machine???? Hard. It actually untwists as it goes thru the machine. All I can say is it's a good thing I only had to stitch around 7 appliques and they weren't big. Next time I want a metallic I'll buy something else. This stuff is going to my girlfriend that does hand embroidery!!

I thought there were only two twists to spools. Regular American thread untwists correctly when the spool is in an upright position. European twists (crosswound spools) untwist correctly when the spool is in a horizontal position on the machine. Maybe this is the problem you encountered?

The other thing to consider is that machines require stronger thread. Many metallics cannot stand up to the wear-and-tear of going through the needle eye multiple times on the machine. That may be why the spool was labeled for hand embroidery only -- not strong enough, therefore likely to fray when put through the rigors of a machine.

The two twists are Z twist and S twist. That's how the strands of the thread are twisted together, either right or left. How it come off the spool isn't the twist. Using that thread in the machine literally untwisted the strands of the thread before it got to the needle.

edited to add: thread twist info

https://www.superiorthreads.com/educ...st-definitions