Granny square jumpers and cardis are SO on trend right now it's ridiculous, and they're some of the easiest things you can make when you're crocheting. These patterns really are just a case of making the motifs, sewing them together and adding a bit of width and length on at the end.
This has been crocheted in King Cole Cottonsoft DK, a 100% cotton yarn in a gorgeous range of colours. You could use any King Cole DK yarn, though, and I'm thinking it would be super cosy in the Merino Blend DK...
