my DH has made them for me. he got some thin acrylic from china town in nyc and then he cut thru it completely to make the design and then he adhered those pieces to thin acrylic.
it was an easy way of making sure the depth was consistent across the entire pattern.
i always use a small stitch length regardless of doing boards, pantos, free hand, etc.
boards and pantos are a very quick way to get a quilt done - its the ruler work and free hand designs that take up the time.