Originally in the Interweave Crochet Spring 2009 issue, the Amazing Grace Wrap is made of SWTC's A-maizing Corn fiber yarn. Though the yarn might be discontinued (I couldn't find it on their website), a good substitution might be SWTC Bamboo. Make a swatch in your stash yarn and then make a decision. If I were going into my stash to give it a go and I didn't have the SWTC Bamboo, I might try Caron Spa.
What was I thinking? Again, like the Beach Sarong, I was thinking Honeymoon (with a capital H). I originally designed this sweater to be a bed jacket, a pretty robe-like cover up for something a little more comfortable. Small join as you go motifs let you easily make it bigger or smaller in 2-3" increments. Side slits give it movement.