Well, I'm still whipping along with the Christmas quilt. I've nearly finished quilting the center blocks and soon will be starting on the boarder. As you can see (below) using the dark green thread has been an interesting choice (thank you for suggesting it, Pauline!) - as it makes the quilting show up very nicely on the reverse side:
What's happened here?
A big goof, that's what.
When I come to the end of a thread and tie off, I "bury the knot" - which basically means pulling the thread a bit tight, tying off, and then pulling so that the knot pops inside the top/batting/back sandwich, effectively hiding it from view. But as I've been working on this quilt, I've pulled too tightly - and thus causing the knot to pop too far in, actually removing a stitch in this case.
Clearly I'm going to need to take a lighter hand with this as I continue, or the back is going to look pretty awful.
So there you go - another lesson learned.