If you're worried about the label bagging after many washings you might think about using a double-sided interfacing to tack it down. I also use a triangle shaped label but not quilt that large. I have a template in my Embird program that I add all my lettering into, then stitch a one-sided iron-on interfacing to tack down the edge that will be handstitched as the other 2 sides will be stitched along with the binding.