Little Miss Pink Puff is designed for a preemie size baby approx 2 lb (1 to 3 lb)
The puff st makes the little sweater just a bit fancy.
If you are running short of your main yarn, the puff stitch can be also made over 2 dc in stead of the 3 dc puff st included in the pattern instructions.
You can barely tell the difference but there is a weight difference of 8 grams using the 2 dc puff stitch.