I have written an additional entry on sleeve cap ease. After reading this entry be sure to check out Reduce/Remove sleeve cap ease pt. 2.
Melissa wrote some comments on my blog entry
A Problem with Cap Sleeves:
I was really excited when I found your blog on the children's sleeve draft from Armstrong's book. I have been working on a project for weeks now and I'm having a lot of trouble with the sleeve. Starting with the Basic Sleeve Draft, I found there was too much ease and took 2cm off the bicep measurement when I read that you take the ease out. But my worry is the shaping of the sleeve cap, it just doesn't look right to me. Even before I took out the ease, it looked like the under arm shaping was really short. When I compare it to bought patterns and the pictures in the book, it just looks like the notches are really low, and there is a very small amount left to go under the arms. I have tried a zillion things and it's been driving me crazy and I hope you might be able to shed some light on my sleeve shaping problem. Thanks so much!
I responded:
One thing that is probably causing you trouble is the placement of your notches. The notches should match up with the notches on your bodice. They don't necessarily imply that is where you should start easing. Home sewing patterns use those notches to indicate the start and end of easing and thus some of the confusion.
And just as an aside, There is more than one way to remove ease. You can lower the sleeve cap, fold out extra (like a tuck), or shorten the bicep at the underarm seam. I'm sure I did some combination of the above.
This is my promised tutorial. Even though I prefer the Armstrong shaping for cap sleeves, it still leaves too much ease. If you draft the sleeve exactly as outlined in her book, you will have to correct your draft by reducing or removing that ease. On page 68 (second edition) she explains that a sleeve should measure 2 inches bigger than the bicep and have an average of 1.5 inches of sleeve cap ease. On pages 69-70 she illustrates how to reduce/add ease to your sleeve. As I have stated before 1.5 inches of ease is simply too much. Some fabrics require 0.25 to 0.5 inches of ease, but not much more. Armstrong does use the notches to indicate easing. If your sleeve has no ease then the notches are just match points.
Just a few more words before you get to the drawings. This is just my method - Armstrong's is similar. My hope is to just illustrate the principle and not hard fast rules. You can have ease, if you choose, thus the tutorial is on how to reduce or remove the ease. You can use this same method to fix the patterns from the Big 4 - which notoriously have too much sleeve cap ease.
Before you can remove/reduce sleeve cap ease, you need to know how much ease the sleeve already has. To do this you need to "walk" the sleeve cap along the armscye -
without seam allowances. This is one of the few times I actually remove seam allowances when pattern making because they actually might get in the way. Align the center sleeve notch with the shoulder seam and walk the pattern along until you get to the underarm seam. Armstrong does this procedure just the opposite by starting at the underarm seam and moving toward the shoulder. Either way will work and her method is probably better. I usually do this in a CAD environment and my brain says start at the shoulder. It doesn't really matter so do what you think is right.
More walking.
Still walking. You can see at this point that my underarm notches meet up. This won't be true in the real world - this is just how my drawing ended up. When I am done altering the sleeve, I move the notches where I need them to be. Right now my goal is to get the sleeve cap and armscye to be the same distance. This is where the Armstrong method might work better for you as the underarm notches don't move.
Finally done walking. Now measure any of the sleeve cap that is left over. This is how much ease you have on the front. Yes, sleeves have a front and a back and I only walked my sleeve along the front armscye. You will need to repeat the procedure since most of you will have assymetric sleeves. My sleeves tend to be symmetric for children so I only have to walk the pattern on one side. Make sense? Now that you know how much ease you have, you can decide how much to remove.
This is where things can get a little fiddly... There are a few different ways to remove sleeve cap ease. I usually use a combination of these methods because I want to maintain a nice sleeve cap shape. Not too flat and not too round. My eyes have been trained to recognize a good sleeve cap shaping and it is not something I can pass along to you. You will have to experiment a little bit to see what works best. Try to keep the convex and concave curves balanced (again, how to explain that?). In this drawing I show two places to reduce ease. The first is to shorten the bicep line by moving in the underarm seam. Armstrong's extra 2 inches is too much for children. It may be too much for adults too. It all depends on your desired fit. The next place to remove ease is to lower the sleeve cap height. With my cap sleeve, I lowered the sleeve cap height at least 1/2 inch and re-drew the cap. Again it depends on your fit and the shape of your sleeve to begin with.
Another way to reduce sleeve cap ease is to split the pattern and overlap it - similar to these drawings (remember I am only working on the front side so don't forget to do the back). Redraw the sleeve cap. This method reduces the bicep but may help preserve the cap shaping.
As I stated before, I probably did a combination of these three methods so that I didn't do anything too drastic. It will take subtle changes to distribute the ease reductions to retain a nice sleeve cap shaping. Finally, check your notch placement on the sleeve and move it to where it should be.
Any questions?