Raglan sleeves are knit seamlessly with diagonal shaping lines, while set-in sleeves use curved armholes and shaped sleeve caps for a tailored look. Top-down raglan construction became popular in the 1980s with Elizabeth Zimmermann's innovations, and today both methods are widely supported by pattern tools like La Maille. This guide compares construction, difficulty, fit, and aesthetics to help you choose the right sleeve type for your next project.
What's the Difference?
Raglan sleeves have diagonal seam lines that run from the underarm to the neckline. The sleeve and body are shaped together, usually knit seamlessly from the top down or bottom up.
Set-in sleeves have a curved armhole and a shaped sleeve cap that fits into it. The sleeve and body are typically knit separately and then seamed together.
These aren't just construction differences — they affect fit, appearance, and the knitting process itself.
Raglan Sleeves: Pros and Cons
Advantages
Easier construction: Raglan shaping is straightforward — regular decreases along four diagonal lines. No complex sleeve cap shaping required.
Often seamless: Most raglan patterns are worked in one piece, either top-down or bottom-up. Minimal or no seaming.
Easy to try on: Top-down raglans can be tried on as you knit, making it easy to check fit and adjust length.
Good for beginners: The predictable shaping makes raglans a popular first sweater choice.
Comfortable fit: The diagonal seam allows good range of motion in the shoulders.
Disadvantages
Diagonal lines may not suit everyone: The raglan lines draw the eye diagonally, which can emphasize broad shoulders or a larger bust.
Less defined shoulder: Raglans don't have a clear shoulder point, which can look less structured.
Fit challenges for some body types: People with significantly different front and back measurements may find raglan fit tricky.
Limited style options: The diagonal line is always visible, limiting design flexibility.
Set-In Sleeves: Pros and Cons
Advantages
Tailored appearance: Set-in sleeves create a defined shoulder line for a more polished, structured look.
Flattering for many body types: The curved seam follows the natural shape of the shoulder and can be very flattering.
Design flexibility: Without diagonal raglan lines, you have more freedom for yoke patterns, colorwork, or texture.
Better fit control: Separate pieces can be adjusted individually. Wide shoulders? Adjust the body. Thick upper arms? Modify the sleeve.
Disadvantages
More complex shaping: The curved armhole and sleeve cap require careful shaping and more attention to the pattern.
Requires seaming: Set-in sleeves are almost always seamed, which some knitters dislike.
Can't try on while knitting: With separate pieces, you can't check fit until you've seamed everything together.
More finishing work: Seaming requires skill to look good. Poor seaming can ruin a beautiful sweater.
How to Choose
Consider these factors when deciding:
Your Body Type
Raglan works well for: Narrow or average shoulders, athletic builds, people who prioritize comfort and mobility.
Set-in works well for: Broad shoulders (the defined shoulder can balance proportions), larger busts (no diagonal line drawing attention), those who prefer a more tailored look.
Your Knitting Preferences
Choose raglan if you: Prefer seamless knitting, want to try on as you go, are a beginner, or dislike seaming.
Choose set-in if you: Don't mind seaming, appreciate tailored construction, want more design flexibility, or enjoy the puzzle of sleeve cap shaping.
The Garment Style
Raglan suits: Casual sweaters, sporty styles, relaxed fits, top-down seamless designs.
Set-in suits: Dressy cardigans, structured pullovers, vintage styles, garments with yoke colorwork or texture.
A Third Option: Drop Shoulders
Worth mentioning: drop shoulder construction is even simpler than raglan. The body is a straight tube, and sleeves attach without any shaping. Very easy to knit, but creates a boxy, oversized fit.
Choose drop shoulder for: Casual, oversized styles; very simple construction; beginning knitters.
Avoid drop shoulder for: Fitted garments; tailored looks; showing off your figure.
Construction Methods
Raglan Construction Methods
Top-down seamless: Cast on at the neckline, increase along four raglan lines as you work down, separate body and sleeves at the underarm. Most popular method.
Bottom-up seamless: Knit body and sleeves separately to the underarm, join all pieces, decrease along raglan lines to the neckline.
Bottom-up seamed: Knit pieces flat with raglan shaping, seam together. Less common but useful when flat knitting is preferred.
Set-In Sleeve Construction Methods
Pieces worked flat: Traditional method. Knit front, back, and sleeves separately with appropriate shaping, then seam together.
Body in the round: Knit the body circularly to the underarm, then work front and back flat for armhole shaping. Sleeves seamed in.
Contiguous set-in: Advanced method where set-in sleeves are worked seamlessly using short rows. Combines set-in look with seamless construction.
Which Is "Better"?
Neither. It's entirely about what suits your project, your body, and your preferences.
Some experienced knitters exclusively knit raglans for the seamless construction. Others wouldn't dream of giving up the polished look of a well-executed set-in sleeve.
If you're unsure, try both on different projects. Many knitters develop a preference but appreciate having both skills.
Using AI Pattern Generation
When generating patterns from photos using tools like La Maille, you'll get a pattern based on the construction visible in your source photo. If you photograph a raglan sweater, you'll get a raglan pattern. For a set-in sleeve sweater, you'll get set-in sleeve shaping.
Not sure which construction your inspiration sweater uses? Look for:
- Raglan: Diagonal seam lines from underarm to neck
- Set-in: Curved seam that follows the shoulder and drops into the armhole
- Drop shoulder: No shaped armhole; sleeves attach to a straight body edge
Frequently Asked Questions
What's the difference between raglan and set-in sleeves? Raglan has diagonal seams from underarm to neckline; body and sleeves shape together. Set-in has curved armholes with shaped sleeve caps; pieces are usually seamed.
Which sleeve type is easier to knit? Raglan is generally easier — regular decreases along four lines, often seamless. Set-in requires curved armhole shaping and a shaped sleeve cap, plus seaming.
Are raglan sleeves flattering for everyone? Raglan's diagonal lines can emphasize broad shoulders or larger busts. Set-in sleeves create a more defined, tailored shoulder line that flatters many body types.
Can I convert a raglan pattern to set-in sleeves? Technically yes, but it's complex — all shaping changes and you'll need to calculate sleeve cap shaping. Easier to find a pattern in your preferred construction.
Which construction is more comfortable? Both can be comfortable. Raglan allows slightly more shoulder mobility due to the diagonal seam. Set-in can feel more structured. Personal preference matters most.
Ready to knit your next sweater? Try La Maille — upload a photo of any sweater style and get a custom pattern with the right construction for that design.