many commercially made (mass produced) quilts are done with 1/8" seams. if the fabric is sturdy, it'll be fine.
just to be on the safe side, get some Fray Block (by june tailor) or Fray Check and treat all the seams with it. do it on the back, of course. i prefer the Fray Block because it come out of the tube more easily than Fray Check comes out of the bottle. much faster application and don't need as much.
they both dry clear.