How To Draft A Sleeve Sloper

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)

tags: Construction, Fashon, Pattern Making Comments: 33

33 Comments
  1. Alessa

    Oh wow, some interesting facts there, I didn’t know half of that! :) Thanks for the tute, I’m looking forward to part two!

    Btw, to join the Family Fashion Archive, I need your flickr name to send you an invite, or you can go to the page directly (http://www.flickr.com/groups/1947777@N21/) and request one!

    Reply
    • maddie

      I too was surprised when I started working in technical design that sleeves and armholes were not what I was taught. It went agains everything I learned in textbooks and school!

      Thank you for inviting me to the Flickr group. I’m excited to share my families wacky sense of style.

      Reply
      • barbara

        i see that the cap heights increase in increments of 1/4″. is that tue of plus sizes as well?

        Reply
        • Maddie964

          Barbara,

          Sorry for the delay in responding. Seriously.

          As for your question… to be honest… I’m not sure. I had to think about it for a couple of days. Although body WIDTHS (not LENGTHS – plus size grading usually effects widths and not lengths) grade differently for plus sizes, I don’t know if this would apply to cap height, which is a length POM (point of measure). If you ask me and if I use common sense, sleeve cap height would not be different for plus sizes because it deals with LENGTH and not WIDTH. Does this make sense?

          Reply
          • barbara Rosenblatt

            after emailing back and forth with you over the last few days about a full upper arm, as we agreed, this is what i did:
            using an old TNT pattern i.e. one that used to fit me before i put weight on my arms, i slashed across the cap, leaving a hinge, and from top to bottom, leaving a hinge only at the top. the reason for the top hinge is that on my arm the weight begins about 1″ below the shoulder joint so i don’t need the full adjustment at the very top.
            that made the wrist end very wide for a fitted sleeve but i altered that by decreasing the width starting approximately at the elbow (i had to guess at this initially) and coming back to the original width. after all the slashing and spreading, i had 1″ top – bottom and side – side more than i started with. when i tried on the sleeve, it was too loose for a fitted sleeve. i did it over and only slashed and spread 5/8″. i was happy with that, and i had to narrow to the wrist less. also in the tying on, i was better able to determine where to begin making the sleeve narrow. i made the wrist as narrow as it was when i used to wear it and was happy with that. after not wearing fitted sleeves for a long while, it will be a nice change to have something different in my closet.
            thanks for your opinion and encouragement. i was thinking it was time to spend the $20 for another pattern that would have required new alterations. so here i am with a sleeve that will fit existing patterns and $20 in my pocket. win-win!

    • maddie

      I know it’s Friday, which means I’m one happy gal today, but your comment made my day. Thank you, thank you, and thank you again!

      Reply
  2. liza jane

    Oh, wow! So much great information. Thanks so much for sharing your knowledge. I’m excited to read part two.

    Reply
  3. Kristen

    I read somewhere – can’t find it now! – that you shouldn’t ease at the top center of the sleeve cap because of something to do with the crossgrain. So you only ease the parts that are cut on the bias/close to bias. I hadn’t seen that article on the Armani coats, but I’m glad you mentioned it!

    Reply
  4. Nethwen

    Why do you say to make the bottom of the sleeve, presumably the wrist, 2 inches smaller than the bicep instead of the measurement of the wrist?

    Oh, and marking the halfway points on the sleeve cap? Helps so much when drawing the curves! I never heard before to mark this point and spent way too much time trying to guess at getting the curve juncture in the right place.

    Reply
    • maddie

      Hi Jill,

      This is just a “textbook” rule or standard. Because the wrist is the smallest part of the arm, if you use the wrist measurement you will not be able to get the sleeve off (it has to go over the hand, which is bigger than the wrist). If you want to use a more accurate/real world method (rather than 2″ less than the bicep), you can measure around the fullest part of your hand (usually just below the knuckle) and use this is the sleeve opening measurement. Using this measurement, you will still be able to get the sleeve off.

      I’m glad to hear that marking 1/2 between sleeve caps helped you draw a nice sleeve cap shape :)

      Reply
  5. Jessica Crapo

    what great info!  Going to give it a go and read the armani article.

    Reply
  6. Katrina Hueniken

     thankyouthankyouthankyouthankyou! Your blog is a godsend for tackling fit issues.

    Reply
  7. MuMinah Saleem

    You have developed an absolutely delightfully informative site! May you be Blessed to continue to build it up!

    Reply
  8. Lynn

    I am trying to draft a sleeve for a knit cardigan which I will be machine knitting. Many knit fitting books draft the front and back slope of the sleeve cap identically. When you were working with knits how did you draft your sleeves? Did you draft a distinct front and back on the sleeve cap or did you make the back and front slopes of the sleeve cap identical?
    Thank you for your help, Lynn

    Reply
    • Maddie Flanigan

      When I worked with knits, the front and back sleeve caps were almost the same shape and this is because the fabric stretches to fit the shape of the shoulder. Because a woven doesn’t stretch like a knit, shape has to be built into the sleeve cap to fit over and around the shoulder. Does this make sense?

      Reply
  9. Piper

    Thank you so much. My sleeves turned out great!

    Reply
  10. Pingback: How To Correct Armhole Balance - Madalynne

  11. Pingback: sleeve cap ease

  12. Tabitha Chen

    On sleeve cap height, it says to subtract the underarm length from the overarm length. My result was about 4 inches. But then it has what look like measurements for the heights of the different sizes, and they’re all larger. Am I doing my measurements wrong? Also, I’m a little confused about the notch at the elbow. It’s a dart, right? But what purpose does it serve?

    Reply
    • Maddie Flanigan

      Hey Tabitha,

      Yes, overarm length minus underarm length equals sleeve cap height but you DON’T measure underarm length (you calculate it -this measurement would be VERY hard to measure) and this measurement IS NOT NEEDED to draft the sleeve (only overarm and sleeve cap height are). BUUUTTT if you want to know your underarm length, SUBTRACT the sleeve cap height (in my chart) from your overarm length (which you measured) to get underarm length. Does this make sense?

      The purpose of the elbow dart is to help the sleeve pivot forward just as arms pivot forward. If you stand sideways in front of a mirror, you will see that your arms don’t hang at a 90 degree angle – they pitch slightly forward. The sleeve dart is a little antiquated but it’s good to start out with it (you can transfer the dart elsewhere later)

      Reply
      • Tabitha Chen

        I think I get it. But with the size I wear, there’s a lot of excess around the armhole. Could I go down a size for sleeve cap height?

        The sleeves I’m wanting to draft a pattern for are slightly flared as opposed to more fitted. Can I leave the dart out?

        Reply
        • Maddie Flanigan

          Are you drafting a sleeve for a sloper or for a garment? I ask this because you wrote that there is a lot of excess around the armhole and there shouldn’t be on a sloper. A sloper is very fitted with only enough wiggle room to move slightly. This tutorial is for drafting a sleeve sloper and it will only fit on a front/back bodice sloper. The process for drafting a sleeve to fit a garment is different.

          Reply
  13. Chinasa

    Thank you a billion times this is the only thing that actually helped me! So one last question. Do i just measure where the notches are and mark it to the bodice so i can match it up later when i sew it together? hope i made sense

    Reply
    • Maddie Flanigan

      Yes, you measure and mark where the notches should be on both the sleeve and bodice. Example: if the BACK sleeve notch measures 2″ from the underarm seam, then the BACK armhole notch should measure 2″ from the side seam. Does this make sense?

      Reply
      • Chinasa

        Yes it makes sense! Thanks!

        Reply
  14. maria

    Awesome tutorial, just what I needed. Thank you!!! :)

    Reply
  15. kailamcarlone

    thank you so much

    Reply
  16. Asmi

    Very helpful..Tq..

    Reply
  17. Kari Morgan

    For the life of me I can’t find the instructions for finding the Y point. No one else seems to have mentioned this, so I’m wondering if there is some duh thing that everyone knows except me?

    Reply
    • MaciNic

      Hi Kari, I read Y as being the end point (1″, or dart width, past x) of: Redraw lower back sleeve line by connecting points W and X and extending it down 1” past point X (to compensate for dart intake)

      Reply

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