At markets, in feedback and on social media I hear women asking fashion labels for ‘real' sleeves. Not all women want sleeves and I'm not advocating that anyone should ‘cover-up'. But, if you feel more comfortable and confident when you've got coverage to the elbow, then I can totally relate. So let's talk about sleeve types.
Sleeve A is what you'd find on a Shell Top. It's not a sleeve per se; it's an extended shoulder. From a designer's and maker's point of view, this style is awesome. They can be longer or shorter and you have two pattern pieces and two pieces of fabric for an entire garment. When this style of sleeve is longer they're often called Kimono Sleeves. Shell Tops help keep indie fashion affordable because they are faster to sew and cut and use less fabric than some other options. .
Sleeve B is a Raglan Sleeve. The top of the sleeve goes all the way up to the neck. Sleeves like this allow for some funky pattern work. For example, you can have a plain bodice (the front and back pieces that cover your torso) and fun/colourful/sparkly etc sleeves - there are so many options. Raglan sleeves can be any length, from looking almost like a singlet to all the way down to your wrist. The length affects how much fabric is used.
Sleeve C is a Set-In Sleeve. These are generally fiddlier to sew than other styles, particularly on woven (non-stretch) fabric. Set In Sleeves are attached to the bodice at the armhole. These sleeves can also be any length from the cap, to full length and anything in between, and this affects how much fabric is used. Set In Sleeves can cost more to produce as they use more fabric and take longer to manufacture (cut and sew). .
Set In Sleeves are my favourite to wear and I use them a lot in my designs. They have a seam at the shoulder that gives me definition i.e. this is where my shoulder stops and my arm begins (not just a continuous curve from my neck down, like I get with Raglan or Kimono sleeves). And they can cover my upper arms comfortably - this is a bonus in summer as it protects my skin, and I feel more confident and less conscious when I wear them. .