Mastering the Raglan Sleeve: A Definitive Pattern Drafting Guide
The raglan sleeve is a timeless and versatile design element in fashion, celebrated for its comfort, distinctive diagonal seam, and elegant drape. Moving beyond the standard set-in sleeve, the raglan creates a continuous line from the neckline to the underarm, offering a unique fit that is both sporty and sophisticated. While it may appear complex, drafting a perfect raglan sleeve pattern is a skill attainable for any dedicated pattern maker. This guide will take you from a basic bodice block to a flawless raglan pattern, providing a clear, step-by-step methodology that is both practical and precise.
The Foundation: Your Basic Bodice and Sleeve Blocks
Before you can draft a raglan, you need a solid foundation. This guide assumes you have a well-fitting, basic bodice block (front and back) and a corresponding single-piece sleeve block. These are your essential starting points. Your bodice block should have standard shoulder and side seams, while your sleeve block should be drafted to fit the armhole of that bodice perfectly.
For our examples, we will use a standard quarter-scale measurement system, but the principles apply to any scale. Ensure your blocks are clean, with all key points clearly marked: center front, center back, shoulder points, neckline points, side seams, bust points, and underarm points. On your sleeve block, mark the sleeve cap height, bicep line, and underarm points.
The Anatomy of a Raglan: Understanding the Seam Lines
A raglan sleeve is defined by its two primary seam lines: the front and back raglan seams. These seams originate at the neckline and curve downwards to meet at the underarm. The key to successful drafting is understanding how to transition the shoulder and armhole of your existing blocks into these new, diagonal seams. The raglan is not a separate piece; it is an extension of the bodice and the sleeve. The final pattern will consist of a front bodice piece, a back bodice piece, and a single sleeve piece that incorporates both the front and back raglan seamlines.
Drafting the Front Bodice Raglan Seam
This is where we begin transforming your front bodice block.
Step 1: Locate Key Points
Lay your front bodice block flat. Locate and mark these crucial points:
- A: The shoulder point at the neckline.
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B: The shoulder point at the armhole.
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C: The underarm point.
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D: The neckline point at the center front.
Step 2: Define the Shoulder Dart (Optional but Recommended)
If your front bodice has a shoulder dart, it needs to be closed or transferred. For raglan sleeves, it’s best to pivot or rotate the dart into a different position, such as the side seam or armhole, to maintain the clean lines of the design. To simplify the process, we will draft the raglan from a dart-less shoulder for this guide. If you have a dart, close it by pivoting the pattern piece. This will make your shoulder line a single, continuous line.
Step 3: Establish the Neckline Position
The raglan seam starts at the neckline. The exact point is a design choice. A classic raglan seam starts about 1/2″ to 3/4″ in from the shoulder/neckline point (A). Mark this new point as E. This small shift prevents the neckline from becoming too wide and offers a better fit. For a more dramatic look, you can move this point further inward, but for a standard fit, the 1/2″ to 3/4″ rule is a solid starting point.
Step 4: Draft the Raglan Armhole Curve
The raglan seam isn’t a straight line. It has a slight curve to accommodate the natural shape of the body and arm.
- Find the midpoint of the original shoulder seam (A-B). Mark this as F.
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Measure 1/2″ to 3/4″ down and perpendicular from the shoulder seam at point F. This is a crucial point for shaping the curve. Mark this new point as G.
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Using a French curve or a freehand curve, draw a line from point E (the new neckline point) through point G and down to point C (the underarm point). The line should be a smooth, gentle curve. Avoid making it too sharp or too straight. This new line, E-G-C, is your front raglan seam.
Step 5: Separate the Pattern Pieces
Now, cut along the newly drafted raglan seam (E-G-C) and the existing shoulder seam from E to A. The portion of the pattern piece that contains the original shoulder and armhole is now separated from the main front bodice piece. This small piece will be transferred to your sleeve pattern later. The remaining front bodice piece, with its new raglan seam, is now complete.
Drafting the Back Bodice Raglan Seam
The process for the back bodice is similar to the front, with minor adjustments.
Step 1: Locate Key Points
Lay your back bodice block flat. Locate and mark:
- A’: The shoulder point at the neckline.
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B’: The shoulder point at the armhole.
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C’: The underarm point.
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D’: The neckline point at the center back.
Step 2: Define the Neckline Position
Just as with the front, we need to create the starting point for the raglan seam at the neckline. Measure 1/2″ to 3/4″ in from the shoulder/neckline point (A’) and mark this as E’.
Step 3: Draft the Raglan Armhole Curve
- Find the midpoint of the original shoulder seam (A’-B’). Mark this as F’.
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Measure 1/2″ to 3/4″ down and perpendicular from the shoulder seam at point F’. Mark this as G’.
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Using your French curve, draw a line from point E’ (the new neckline point) through point G’ and down to point C’ (the underarm point). This is your back raglan seam.
Step 4: Separate the Pattern Pieces
Cut along the newly drafted raglan seam (E’-G’-C’) and the existing shoulder seam from E’ to A’. The small piece containing the original shoulder and armhole is now separated. This will be joined to the sleeve piece. The remaining back bodice piece is now complete.
Drafting the Raglan Sleeve: The Union of Three
This is the most crucial part of the process. We are now going to take your original sleeve block and combine it with the two small shoulder pieces we just cut from the front and back bodices. This is where the magic happens.
Step 1: Prepare Your Sleeve Block
Take your basic, one-piece sleeve block. Mark the grainline, the bicep line, and the underarm points. We’ll call the front underarm point H and the back underarm point I. Mark the center of the sleeve cap as J.
Step 2: Join the Front Shoulder Piece
Take the small piece you cut from the front bodice (the piece that contains the original shoulder and part of the armhole).
- Align the underarm point (C) of this piece with the front underarm point (H) of your sleeve block.
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The original armhole curve of this piece should naturally align with the existing armhole curve of your sleeve cap.
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Secure this piece to the sleeve pattern with tape. Ensure there is no overlap and the curves are a smooth continuation of one another. The original shoulder seam (A-B) is now an extension of the sleeve cap.
Step 3: Join the Back Shoulder Piece
Repeat the process for the back shoulder piece.
- Align the underarm point (C’) of this piece with the back underarm point (I) of your sleeve block.
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Align the armhole curves smoothly.
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Secure this piece with tape. The original back shoulder seam (A’-B’) is now the other side of your extended sleeve cap.
Step 4: Draft the Raglan Sleeve Head
The top of your new sleeve pattern is now very wide and has two sharp points from the original neckline points (E and E’). This is your new sleeve head. The seam that connects the front and back shoulder pieces (the part that used to be the neckline) needs to be smoothed and curved.
- Measure the distance between point E and E’.
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Find the midpoint of this line. This will be the center of your new sleeve head.
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From this midpoint, draw a slight, shallow curve upwards. The exact height of this curve is a matter of design, but a good starting point is about 1/2″ to 3/4″ above the E-E’ line. This creates a comfortable, rounded shoulder line that will not bunch up at the neck.
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Connect the ends of this curve back down to points E and E’. This new curve is your raglan sleeve head seam.
Step 5: Refine the Final Sleeve Pattern
You now have a complete raglan sleeve pattern. It is one large piece that includes the front and back raglan seams.
- Trace your newly created sleeve pattern onto fresh paper.
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Mark the front raglan seam (E-G-C) and the back raglan seam (E’-G’-C’) clearly.
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Mark the grainline. The original sleeve grainline should still be your guide.
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Mark the front and back sides of the sleeve for clarity.
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Add seam allowances to all cut edges: the raglan seams, the underarm seam, and the hem.
Drafting a Two-Piece Raglan Sleeve
For garments requiring more tailored detail, like a coat or a blazer, a two-piece raglan sleeve is the preferred method. This allows for greater shaping and a more precise fit.
Step 1: Start with Your One-Piece Raglan Sleeve
Follow all the steps above to draft your one-piece raglan sleeve pattern. This is your foundation.
Step 2: Create the Seam Lines
You will be splitting the sleeve into two pieces. The seam is usually positioned along the top of the sleeve, often called the “sleeve ridge” or “sleeve crown,” and continues down the arm.
- On your completed one-piece raglan sleeve pattern, find the center of the sleeve cap (J).
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Draw a line from the center of the sleeve cap down the length of the sleeve to the hem. This line should be parallel to the grainline. This is your first seam line.
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For the second seam line, which will create the elbow shaping, find the elbow point on your sleeve (this is typically about halfway down the sleeve).
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From the elbow point, draw a gentle curve that sweeps from the front of the sleeve to the back. This curve should be more pronounced on the back half of the sleeve to accommodate the bent elbow.
Step 3: Separate the Pattern
Cut the sleeve pattern along these two new seam lines. You will now have three pieces: a front upper sleeve, a back upper sleeve, and a lower sleeve.
Step 4: Add Seam Allowances and Markings
- Add seam allowances to all new cut lines.
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Add notches to all seam lines to ensure proper alignment when sewing. These are crucial for a two-piece sleeve.
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Label each piece clearly: “Front Upper Sleeve,” “Back Upper Sleeve,” and “Lower Sleeve.”
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Mark the grainline on each piece.
Step 5: Final Refinements
For a truly tailored fit, you can add a dart or a slight curve at the elbow on the back upper sleeve piece. This provides extra room for movement and shaping. Simply add a small wedge-shaped dart to the back piece, about 1/2″ to 3/4″ wide at the elbow line, and close it before adding your seam allowances.
Finalizing and Assembling Your Pattern
You now have a complete raglan pattern: a front bodice, a back bodice, and a single or two-piece sleeve. Before you cut your fabric, take these final, critical steps.
- Walk the Seams: This is a non-negotiable step. “Walking” the seams means physically measuring and comparing the length of the front raglan seam on the bodice with the front raglan seam on the sleeve. Repeat for the back. The measurements should be identical. If there are discrepancies, a small adjustment to one of the curves is necessary. Do this before cutting any fabric.
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Add Seam Allowances: Double-check that all pieces have the correct seam allowance added to all edges that will be sewn. A standard 1/2″ or 5/8″ is common.
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Label and Mark: Label all pattern pieces clearly with the garment name, piece name (e.g., “Front Bodice”), grainline, and number of pieces to cut. Mark notches on all seams, especially the underarm seam, to ensure the pieces align correctly.
Conclusion
Drafting a raglan sleeve is a skill that demystifies the pattern making process. By breaking down the complex diagonal seam into manageable, incremental steps, you can confidently transform a standard block into a unique, comfortable, and stylish raglan design. The key is a methodical approach, precise measurements, and a deep understanding of how each piece of the puzzle fits together. The result is not just a pattern, but a mastery of a fundamental technique that opens up a world of new design possibilities. Your ability to visualize and execute this transformation is what separates a novice from a seasoned pattern maker.