At this stage, I've got each block sewn together and I'm auditioning fabrics for the center of each circle.
Once I've made my center choice, then I have to remove the vellum from the back of each block before proceeding. I've found that if I spray the vellum with water and let it sit for a minute or two, it softens up and is much easier to remove.
Now it's easy to sew the centers to the blocks using invisible thread (I use Madera) and a blanket stitch.
I'm having fun, can you tell?