I've used both and have decided that it really depends on the "firmness" of the fabric that I want to use......both fray easily. I do think the Kona is the heavier blend and I do make sure it is the RK brand. I really haven't found any solid fabric that does not fray a lot. I just finished a quilt from a kit I bought 15 years ago.....(I know, it's old, but I'm finally dealing with some stash). I'm sure it was Kona and it frayed like crazy! I find the Kona almost impossible to use for applique.