Latest knitting project - Trinity Stitch

Here's the knitting project I'm working on currently, it's a throw-pillow cover.

I'm using this fairly cool acrylic yarn that's 20% post-consumer recycled plastic bottles. It's really soft, won't be itchy to lay against on the sofa, and it's washable.

The Trinity Stitch

Works on multiples of 4 stitches.
Row 1 (right side): Purl.
Row 2: Knit 1, *(Knit 1, purl 1, knit 1) all in the same stitch, purl 3 together. Repeat from * across. Knit 1 for last stitch in row.
Row 3: Purl.
Row 4: Knit 1, *Purl 3 together, (knit 1, purl 1, knit 1) all in the same stitch. Repeat from * across. Knit 1 for last stitch in row.
Repeat these four rows for pattern

IMPORTANT NOTE: Many of the instructions that you find on the web for this pattern omit the knit stitch at the beginning and end of the pattern rows. Omitting the knit stitches makes the edges 'wobbly' instead of nice and straight if you are JUST doing the trinity stitch for the entire project.

This pillow cover calls for a cast-on of 82 stitches for a 14 inch pillow.