Well, I have a Janome and it has a plastic cover over a drop-in bobbin but when you're sewing it's covered by the fabric! I get so engrossed that I forget to check in-between steps to check the level of thread left. I had to smile when I read the post because I ran out tonight while sewing trim on a toddler dress. Not a big deal but I was quite a ways before I noticed it. Then I'm mad at myself for not checking!