This is a technique I developed for cutting plastic grocery bags into yarn and also a pattern for knitting the plarn into a mat.

Half blanket, half shawl, this will knit up quickly and keep you WARM. It’s knit with 4 strands of worsted yarn at once. I also used my Boye Needlemaster with EXTRA cables, long enough to make a 60” circular needle. You could use three-four 29” circulars, just be careful that stitches don’t fall off the needles.