Whenever in the past I wanted to create soft edges in a quilt I either used sheers, discharge, paint or zapped some synthetic fabric. But for this lesson I decided to stick with regular cotton and thread. And I can only say that it is difficult to create this effect. For the background I wove 2 pieces of fabric - next to each other in the color wheel - so that they blended nicely. My first idea was to use other pastel colors for the applique, but they simply got lost because of lack of contrast. After some thinking I opted for an open applique. This I made more open by punching a gazillion little holes in it, so that the colors of the background showed through. This only got partly the effect I wanted. Time for drastic steps :-). Using the dark blue thread which I used for quilting the spiral I added lots of additional stitching way outside the shape of the spiral. I admit that I never have done something like this and don't know whether I will ever again do it, but I got the effect I wanted.
The empty space I had on this quilt I used for adding broken lines, 3 vertical and 2 horizontal. More time consuming, but I like how they look like. Looking at this quilt now it is finished I can say it is not the best I ever made, but I think I got the soft edges correct.