A solid white or black background always seem to show the imperfections more.
This may be no worse than you are used to, but with the strong contrast between the B+W, perhaps it is just showing more?
It has been my experience that if I use Best Press throughout, it helps to "seal" the fabric and minimize fraying .... ultimately minimizing the loose threads! And even seems to help put a protective finish to avoid clinging threads!
I don't think you can eliminate them totally, but do the best that you can as you make your quilt. And then do an extra-good job of cleaning it up before sandwiching your quilt and starting the quilting process.
Another tip ... keep your cutting table, sewing and ironing areas cleaned up as you go. if there is lint and threads hanging around they just seem to jump onto our projects!!
