Just like I said here and here, sleeves and armholes are tricky. So many factors determine an impeccably sewn and fitting sleeve – sleeve cap height, sleeve cap width, and sleeve cap ease are three basic ones but the shape of the front sleeve cap in relation to the back sleeve cap as well as the pitch of the sleeve are important factors as well. Achieving a good fitting sleeve goes further than just sewing it well – it is the result of experience and lots of study. A good starting point to becoming an expert on sleeves is to learn about sleeve cap ease.
In my post How To Draft A Sleeve Sloper, I wrote that many textbooks and commercial patterns have too much sleeve cap ease, usually between 1”-1 1/2”, and that the correct amount of sleeve cap ease is ½”-3/4.”. I still stand by what I wrote but I want to make a change to it. During my two and a half years in technical design, I worked in the sweaters, knits, and intimates department. The patterns for the styles we worked on had ½”-3/4” sleeve cap ease (some had none!). This amount of ease worked because of the fabric – knits and sweaters. On a knit or a sweater, the sleeve cap has no “lift” as it does in a woven -it lays close to the body. So it’s no surprise that I held this to be true. But when I was sewing the first muslin for my project, this amount of ease did was too little. The sleeve cap was flat, didn’t “lift”, and looked plain ole ugly! So for the second muslin, I drafted another sleeve so that the sleeve cap ease was 1 3/8” and it fit beautifully! So I am updating the post How To Draft A Sleeve Sloper to say that the right amount of sleeve cap ease depends on the type of fabric and silhouette. Some sleeves require little ease (knits) while some sleeves require a lot of ease (tailored jacket) and this is because some fabrics ease easily (knits) while others do not (suedes/leather) and some silhouettes require more ease (tailored jackets) while others do not (drop shoulder). That’s why it’s important to know how to increase or decrease sleeve cap ease, which I’ll show you next week.
I apologize for writing “misinformation” (I don’t know if i can label it that as my intentions were not such) but that’s what is great about this hobby – it keeps me on my toes and I learn something new every day. I’m also not afraid to admit when something I thought to be true isn’t.