Per Hobbs Batting's website, the fusible is water soluble
Hobbs Heirloom Fusible Batting, so it washes away when you wash the finished quilt. Lots of other important information on that page.
Note that it's apparently fusible on both sides, so you'd want all 3 layers stacked before you start pressing to activate the adhesive.
Hobbs advises quilting no more than 4" apart.
ETA - and you must use a hot, dry iron. If you use steam, it won't stick.
Thanks
@mkc ... Of course, why didn't I think of checking their website!
Sometimes the obvious, just isn't obvious.
I have some fusible, but have no clue as to the brand ... so now you probably already know my next question ...
Is the non-permanency of the fuse, the same for all fusible battings?
Thanks again,
@mkc and Everyone ... with another Happy New Year, too!