I have more than one quilt like this. If you look at the machine applique stitch you will see that it is much like a finished seam inside a garment. It is meant to not come out or let things unravel. I wash mine and the stitches are small enough and close enough together that it doesn't unravel. I use the machine blanket stitch rather than just a zigzag. If you don't know what I mean google it on utube. I learn a lot of my quilting there. The really awesome thing about machine applique is there is so much more option as to the shapes you use because you don't have to think about seam allowances and turning things under.