I made both of these using the sew and flip method. I used batting scraps but made sure they were low loft. I can't say if they were W&N or Hobbs 80/20 or another product. Measurements are given on the original post on this one:
Super simple Quilt as you go placemat
These were freeform shape so no measurement but roughly about the same:
More QAYG placemats