From Forget-me-not Patterns:
Iris is a t-shirt pattern designed for knit fabrics which is easy to sew and easy to wear! If you want to stick with a classic basic, there are plain sleeve options in short and three-quarter lengths. But if you crave something just a little more interesting, there are two pleated options for the sleeves. Both pleat designs feature cleverly intersecting pleats which are surprisingly simple to sew. Iris features a classic women’s t-shirt fit which includes waist shaping without being clingy. The neckline is a classic crew neck.
All sorts of knits work for this design. Emphasise the sculptural details of the pleats in a double knit, or let them drape in a slinky viscose. Or simply sew a classic tee with plain sleeves in a classic cotton t-shirting!