This is how much yarn was left when I finished the shawl.
I started out with a long foundation chain, didn't count stitches but magically ended up with the right number. I then worked what is sometimes called the 'delta' stitch to the end. Delta forms little triangles with 2 double crochets and 2 chains. I can't explain it better, I've never written a pattern. Because of the way deltas are made, each row loses two triangles, one at each end. When I thought I was running out of yarn, I started thinking about a border and didn't like anything I came up with. Until I tried this: slip stich, chain, skip a stitch, slip stitch, chain, skip a stitch .... all the way from corner to corner and back. I think I did about 5 or 6 rows like that. When I could see only a few yards of yarn left, I did one row across the top and ran out of yarn.

The shawl is not rectangular, but it's not a full triangle either. I always think the triangle shawls end up too long, at least on me. This shawl is wide enough to wrap me and long enough to cover most of my back. Just perfect for a not too cold day.
The yarn used is an acrylic I picked up at a sale. There were 5-6 skeins in a bag, no label or brand name. The price was right for me -- $6 for it all! It feels very much like Simply Soft and the colors are nice.
Then, while looking for a plastic bag to store the shawl until I'm ready to wash and give it away, I found another skein. It was tucked away in a bag I had taken with me to a doctor appointment two days ago. So I'm using it to add to the border, making the shawl slightly longer.
I like how the border looks in contrast to the body of the shawl.