OK, I'm machine quilting, everything going along just fine. Stippling along the border, bobbin runs out. Put a new one in and keep sewing. Finished the border and had a look at the back for bloopers. Aargh! All the bit with the new bobbin, about 3/4 of the entire border, looked like loopy needle-punch on a string. Obviously I either threaded the bobbin wrong, or there was a bit of lint in there to muck up the tension. So as I was ripping out all that work, I thought how great it would be if my machine had a warning (flashing red light, loud siren?) whenever the back of the work looked like crap. After all, it gives me a "low bobbin" icon. So would somebody please invent one?
I am still amazed that the machine just kept stitching along with no protest whatsoever, and the top side looked great!