A good half of my summer sewing projects this year feature raglan cap sleeves. The dress I posted about on Friday had them, and the next dress to comes does too. They’re cute and summery, keep my shoulders from burning, and quite simple once you get the hang of it.
The trick to raglan cap sleeves is the gathers at the top of the armhole. This is what gives the sleeve a curved shoulder-like shape. You don’t need a lot of gathering – this isn’t a puff sleeve. But without it you get strange pointy wings that don’t look like a sleeve at all. The gathering is key.
You also need to put the raglan seam in a sensible place. I think having the lowest edge about 1/3 of the way up from the bottom of the armhole, with a strong upward slant looks best. If you put it too low you lose range of motion in the sleeve, and too high just looks silly.
Finally, you want the right curve in both the top and bottom of the sleeve. Essentially, the side of the seam closer to the neck is a straight line angled down toward the armpit, and on the arm side it is curved like a set in sleeve. So for the sleeve, the seam begins high on the neck side and angles gently down, running in a straight line, then curving ever so slightly downward. For the body piece the sleeve attaches to, the seam also begins high on the neck side and runs down at the same angle as the sleeve. As it nears the end of the sleeve it curves down more quickly than the sleeve so that the outside edge of the sleeve gets pulled in ever so slightly, then continues curving down to form the armhole. The back will be more or less the same. Look at the sketch above to see how this all works. The inside edge of the sleeve is a straight line, while the outside edge curves out.
To assemble your raglan sleeve top or dress, loosely gather the center 3″ of the outside of the sleeve until the gathered area is 2″ long. Sew up the side seams of the top. Sew the front raglan seam up. Sew the back raglan seam. Carefully sew bias tape around the edge of the sleeve, starting at the side seam at the bottom of the armpit. Sew bias tape around the neckline. Your sleeves are complete!