had planned to machine applique on to back in random pattern rather than sqs etc
I think appliqueing would make a very heavy quilt. I use a tricot fusible interfacing on the back of each block. That is a knit interfacing that is used in garments. It gives the block a nice body without much weight. I try to keep everything as light as possible as the knit is already heavier than most cotton quilting fabrics. A knit backing would add more weight I think.