I did a search and couldn't find what I needed to know. I have used Essential thread horizontally in my machine but recently had my bobbin making a rattling noise and the top thread snagging once in awhile. the bobbin wasn't Essential. I finally changed bobbins, filled again with the same thread i'd been using and removed the almost empty Essential spool and put a different brand on. no more rattling.
should Essential threads be used vertically at all? I know there is a rule about the different ways thread is wound. ????????