Oh boy are sleeves tricky. Very, very tricky things indeed. In my opinion, a sleeve’s difficulty lies in the fact that a 2D, flat piece of fabric is being made to fit a 3D, rounded object – the armhole. It’s the same difficulty a painter experiences when making a 2D canvas look 3D. Although difficult, it is completely achievable. While painters use perspective to paint a 3D painting, sewers use basting stitches and ease to make a sleeve fit the armhole.

There are many factors that affect the fit of a 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. After sewing many sleeves, you learn what a good sleeve looks like. A good starting point to becoming an expert on sleeves is to draft one. Drawing the curves of the front and back sleeve cap, you will tune your eyes to know the correct curvature and shape of a good sleeve verses a bad one.

This is where I come in. In the diagrams and directions below, I will show you how to draft a sleeve. But the sleeve draft post won’t end there. In my next tutorial (August 2012), I will show how to true the sleeve, ensuring the sleeve cap has the correct amount of ease and how to correct it if it does not. After that tutorial, I will show you an alternative method to drafting a sleeve that I only recently discovered (October 2012). The two methods yield completely different sleeve cap shapes and when I saw the alternative method for the first time, it sort of rattled my world, my pattern making world. I have yet to try the alternative method but I thought this would be a great opportunity to explain it to you while I try it out myself.

Before getting started, let me preface with some facts about sleeves and armholes.

Many textbooks and commercial patterns have too much sleeve cap ease, usually between 1” and 1 1/2”. In some cases, this amount of sleeve cap ease works (tailored jacket) but in most cases, it does not. From my own experience, I have found that the correct amount of sleeve cap ease depends on the fabric and the silhouette. During my two and a half years in technical design, I worked in the sweaters, knits, and intimates department. The patterns for the style we worked on usually 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. For awhile, I held this to be the rule – that all sleeve caps should measure 1/2″-3/4″ more than the armhole. But when I was sewing the first muslin for this project, that 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 a new sleeve that had 1 3/8” sleeve cap ease and it fit beautifully! So in my opinion, the right amount of sleeve cap ease depends on the type of fabric and silhouette. Some sleeves will require little ease (1/2″-3/4″ for knits) while some sleeves require a lot of ease (1 1/2″-1 1/2″ for tailored jackets) 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).

The same goes for the amount of ease for the bicep of a sleeve pattern – it depends on the fabric and silhouette. Some biceps require more ease (1″ on a short sleeve woven blouse) while other require little ease (3/8″ on a knit).

Sleeves should pitch slightly forward. Why? Stand sideways in front of a mirror and let your arms hang freely. You will see that from shoulder to elbow, your arm pitches forward only slightly but from elbow to wrist, your arm more noticeably pitches to the front. Since this is the way the arm hangs naturally, so too should the sleeve. The placement of the shoulder notch affects the pitch of the sleeve and if the sleeve is pitching incorrectly, the shoulder notch is moved forwards or backwards accordingly.

The shape of an armhole is an asymmetrical horseshoe with a flattened bottom (where the side seam meets the armhole). The flattened bottom is critical as it ensures a smooth transition from front armhole to back armhole. This is why in my tutorial about truing the front and back bodice block (click here to see), I wrote that the side seams at the armhole have to be at right angles. If they are not, the armhole will peak up or down at the side seam.

The shape of the front and back sleeve cap is different. The front sleeve cap is more shaped and sits more forward (just slightly) than the back sleeve cap. This is because the ball of the shoulder, a very rounded shape, sits at the front of the arm.

The back armhole is usually ½” longer than the front armhole and this is called the balance of the armhole. To determine if an armhole is balanced, place the front and back bodices side by side with the bottom of the armholes (where side seam meets armhole) butted together or lay back bodice over front bodice with side seams aligned at the bottom of the armhole (where side seam meets armhole). A balanced armhole will have the back armhole “taller” or longer than the front. If this is not the case, there are several ways to fix it and it depends on what is going on. If the balance is off at the top of the armhole, one simple way to correct this is to shift the shoulder seam forwards or backwards by half the difference of the front and to the back armhole  (if the back armhole is 1” longer than the front, reduce back armhole ¼”,increase front armhole ¼”, and shift shoulder notch ¼” backwards). If the balance of the armhole is off at the bottom of the armhole/side seam, it can be corrected by using this tutorial. Again, it all depends on what is happening on each pattern – the balance could be off at the top or bottom of the armhole.

The closer the armhole fits to the body, the more shaped the armhole is on a pattern and the more mobility the sleeve will have. This may not make sense at first but think of an oversize or dropped shoulder sleeve. On such a style, the armhole is less shaped and therefore does not move with the arm as well. When the arm is raised in such a style (oversized/dropped shoulder), the underarm (where the side seams meet the armhole) will “wedge” out. Initially, a pattern maker may want to reduce the bust width at the side seam but all that is needed is to add more shape near the bottom of the armhole.

On the subject of sewing sleeves, here is a cool tidbit…

About three years ago, I read an article in Threads Magazine about the secrets of Armani jackets. Out of all the information written, one fact stood out. In an Armani jacket, there is no ease at shoulder tip – the sleeve is flat at the shoulder seam. I don’t know if there is any rhyme or reason to the secret but it just makes sense. Click here to read the article. It’s really cool.

Okay, let’s get started.

Below are measurements needed for sleeve draft. I did not provide an illustration because I think the measurements are self explanatory. If anyone is having trouble measuring their arm, please let me know and I will provide an illustration.

1. Overarm length – must be measured with arm slightly bent. If it is not, sleeve will appear too short when fully bent or too long when fully relaxed.
2. Elbow length
3. Wrist bone length
4. Bicep plus 1” for ease (I chose 1″ because most sloper are made out of muslin – a woven)
5. Wrist bone plus 1 ¾” (in order to get your hand in and out of sleeve; add more if necessary)
6. Sleeve cap height – use diagram below to determine sleeve cap height for your size

sleeve cap height meaurements How To Draft A Sleeve Sloper

Now, let’s draft…

sleeve step 1 and 21 How To Draft A Sleeve Sloper

step 1 How To Draft A Sleeve Sloper

A-B = Overarm length

A-C = Sleeve cap height

A-D = Elbow length

Square out lines to left and to right from points C, D, and B (doesn’t matter how long; just make sure each line is at least 1” longer than ½ of bicep)

C-E = half of bicep plus 1/2″ for ease

C-F = C-E (other half of bicep) plus 1/2″ for ease

B-G = 2” less than C-E/C-F

B-H = B-G

Connect points G and E and points H and F

Label elbow level I and J as sketch

step 2 How To Draft A Sleeve Sloper

E-K = ¼ of E-C

F-L = E-K

A-M = E-K

A-N = E-K

Square up or down from the following points as follows:

K = square up 7/8” and label O
M = square down 5/8” and label P
N = square down 3/8” and label Q
L = square up 5/8” and label R

With straight ruler touching points O-P and Q-S, mark midpoints and label S and T as sketch

With a curved ruler touching points A, Q, and T and pointing down, draw top of front sleeve cap
With curved ruler touching points F, R, and T and pointing up, draw bottom of sleeve cap
Repeat the last two steps to draw back sleeve cap

Honestly speaking, I was not happy with the shape of my sleeve cap at this point. Because my bicep is so small, my sleeve cap looked too narrow and tall. So I ask that you do the same as I. Eyeball the shape of your sleeve cap and compare it to the one in my sketch. Does it have a similar shape? If it does not, use your instinct at redraw what looks like a correct shape. Doing so may increase or decrease the amount of ease on the sleeve cap (making a line more curved increases line length; making a line less curved decreases line length) but don’t worry too much about that right now.

sleeve step 3 How To Draft A Sleeve Sloper

step 3 How To Draft A Sleeve Sloper

I-U = ½ I-D

U-V = 3/8” squared down from U

I-W = 1” (dart intake)

Connect points I and V and V and W

G-X = 5/8” (on wrist guideline)

H-Z = 5/8” (on wrist guideline)

Redraw lower back sleeve line by connecting points W and X and extending it down 1” past point X (to compensate for dart intake)

Connect point Y and Z

Redraw lower front sleeve line by connecting points Z and J and making sure line transition smoothly into upper front sleeve

Mark back sleeve cap notches with 2 lines (spaced ½” apart) with upper line 1 1/8” below point S (back sleeve always has 2 notches)

Mark front sleeve cap notches with 1 line that is 1” below point T (front sleeve cap always has 1 notch)