The possibilities of working with felted fabric are limitless, just like the artist's/designer's imagination. Here's Lanette Freitag of FeltLOOM Demonstrating creation of felted wool rugs at Kentucky Artisan Center at Berea.
Detail of folded back edge - she made it with a thick layer of Shetland wool on the back for strength and squishyness (although it could be squishier. maybe I should have added a layer of Finn wool in there too).
Linen Stitch: Works on an even number of stitches. Row *Knit slip 1 with yarn in front. Repeat from * across, Row *Purl slip 1 with yarn in back. Repeat from * across. Repeat these two rows for pattern. When slipping stitches, always slip as if to purl.