As to the velvet, I actually had all four corners of each block sewed on (after a big fight with the velvet on each block), and when I went to sew the sashing (which is a batik), if one didn't slide, the other slid! Even when I pinned it! I sat and pulled every stitch out of the velvet -- cause I loved the heart blocks! I'm glad I finished it.
Kudos to anyone who completed that quilt with the velvet! I'm a beginning quilter and I couldn't handle it. Maybe sometime in the next 20 years LOL :)