I use variegated threads all the time in my quilting. The brand on my machine at the moment is Coats and Clark, I have used Star, Gutermann, Valdani, Connecting Threads's Essential, though I have one spool of blue and white that my machine did not like at all, which is why I have the Coats and Clark in the machine, I needed another blue and white and that's the closest to the previous color. I have used plenty of other Essential Threads with no problem so I don't know what happened. I have only used one King Tut, it is good thread but hard to find in my area. The think I have mostly YLI's in my thread collection in the variegated.