Filet crochet is usually done with crochet thread. I chose to use yarn because I wanted more coverage than thread would allow. (I bought a green pillow that didn't match my décor as well as I thought it would.) For those of you unfamiliar with filet crochet, all stitches are either a double crochet or a chain and skipped space.
Chain 45
Row 1: sk first 3 ch (counts as first dc), dc in second chain and across (42 sts)
Follow the chart for the rest of the directions.
Download: download chart PDF