How a Suit Should Fit: Pattern Making 101

September 9th, 2015

As we pour over the final details of our online tailoring collection and prepare for the launch of AOS Bespoke in October, it’s a perfect time to discuss the foundations of pattern-making.

Every garment in fashion, high-end or low-end, begins with a pattern. A pattern is a series of geometric shapes drawn to exact scale (on paper if you’re old school, but mostly on CAD spoftware now) that acts as both a “stencil set” to trace onto a chosen fabric as well as a set of “official tailoring instructions” that describes in detail how the garment should be manufactured.

To give you a more in depth idea of what a pattern looks like, here’s a look at the one I’m working on for the bespoke linen suit that I’m in the process of hand-making myself.


My jacket pattern has a traditional 7 pieces (some very shapely jackets have 8, since a split side-body offers an additional seam to curve). The key here is that the patterns are properly adjusted for the client (in this case, myself) with special concern to posture, head placement, shoulder slope and the balance of the client’s girth (front/back). It’s also crucially important that the adjustments for the client are accounted for across all of the pattern pieces. Making even the slightest change to the shape/dimensions of one of the pieces requires that you adjust the other pieces accordingly. There are countless rules, exceptions, and opinions when it comes to proper pattern-making. This is why certain shops have a “house cut” and why takes a lifetime of experience to become a master tailor – and, consequently, why most good tailors are of retirement age.

Because the bespoke pattern-making process is so complex, and the human form has so much unique intricacy, it is much more accurate for a tailor to perform a cloth fitting rather than than simply relying on a measuring tape. Measurements won’t tell you how a cloth will sit on the shoulders, or the neck, or the the lower back even. This is why, with AOS Bespoke, each of our clients will begin with a custom-made fitting garment to asses their unique body shape… More on our process, and “fitting” versus “measuring”, later. Let’s stick to the basics of pattern-making.


The Complete Jacket Pattern

Front Panel

The front panel forms the basis of the jacket and tells us a lot about it’s styling. It includes the chest dart placement (which shapes the jacket by adding suppression from the chest to the waist), the pocket placements, the button stance, the width and shape of the lapels, the fullness of the chest, the height of the armhole, the length of the jacket, the slope of the shoulders, etc. Making a slight change to this pattern piece will make a noticeable difference to the look and feel of the jacket, especially since every adjustment is doubled (the two front panel pieces are cut at the same time from double-layered fabric for absolute symmetry…this is “cutting 101”)

Front facing 

The facing must match the shape of the front, as it forms the inside of the front panels and the lapels (since they roll outward). On a quality jacket it also covers the chest canvas which is hand-set to the backside of the front panel and sits in-between the two layers.

Back Panel

The back panel includes crucial information about the fit of the jacket such as the size of the neckhole (which should be cut to the clients neck size), the height of the collar (relative to the length of the clients neck), the shoulder slopes (which must match those on the front panels), the back of the armholes, the vent placements, etc. It’s also a piece where a lot of shape can be added to the garment, as the long center back seam and the side-panel-seams can all be curved inward to add suppression when sewn together.

Side Body

The side body sits below the bottom of the armhole and is the connection between the front panels and back panels. It’s the obliques of the jacket, if you will. It’s possible to make a jacket without a side body (by making the front and back panels large enough to sew together), but the additional seams of the side body allow for much better shaping.


The collar is a foundational piece of the jacket. In order to achieve a proper fit, it should fit cleanly on the client’s neck, with no gapping, or rolling. The length of the collar piece also determines the gorge line (or height of the lapel notches – which, of course, must be accounted for on the front panels and facings). This pattern piece is typically cut from fabric (topside) and melton felt (underside), although some old-school bespoke tailors also hand-set a layer of canvas in-between them.

Top Sleeve

This is the large, exterior piece of the sleeve. The shape, size and curvature should coincide with the client’s natural standing position. On a good suit the top sleeve also contains additional fabric at the cuff which is used to create working sleeve buttonholes.

Under Sleeve

This is the underside of the sleeve, which faces the side of the jacket. This piece is sewn to the top to create the sleeve before it is set into the armhole of the jacket – which consists of the front panel, back panel, and side body.


I hope this was informative to some. The best part about our new Bespoke line, other than our Articles now being shoppable, is that it offers ample opportunity for us to create more in-depth articles revolving around tailoring, menswear, and quality manufacturing in America.

For those who’ve been asking, I have an official preview of the collection coming up soon! It’s going to be an exciting three weeks…


Yours in style,

Dan Trepanier

Shop Custom Menswear Made in America


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  • Sydney Owino

    Where does someone interested to learn this beautiful art get signed up?

  • Frank Wilder

    Imagination is more important than knowledge – Frank Wilder

  • Style Girlfriend

    This looks like it will be amazing! Congrats, Dan, and the whole AOS team

  • Jeff

    Great piece, Dan!. This just makes me more confident and excited in the line you have coming up.

    Like Juan asked below, could you tell of any good books on tailoring, pattern making, etc? I’ve been thinking about possibly starting to work part time at a bespoke tailors, just to further immerse myself, and would love to hear your insight.


  • LarsBrown.


    The content in these articles is superb, I enjoy every word.
    I’ve recently finished making a bespoke pair of trousers from a beautiful checked wool – they looked like crap, chiefly because the lady helping me insisted I made the bottom of the leg 9″ wide, when personally prefer a 7″ opening.
    However, the process is fascinating and the art of creating your own clothing is sublime.

    I look forward to reading more and, of course, the upcoming collection.

    Thank you as always.

  • Juan Zara

    Hi Dan,

    First of all, I’m loving all the teasers and the previews of the upcoming collection you have been putting up on Instagram. It all looks fantastic and I particularly enjoy and applaud the choice of drawing inspiration from the American classics. The “updated Trad” aesthetic is extremely pleasing to me, and nails the modern but timeless look I guess most of us readers are going for.

    Second of all, as a self-learner who’s gone from only being able to hem his jeans to successfully sewing a pair of trousers (although they didn’t turn out as I’d hoped) on a self-made pattern, I must say this content right here is, by far, the most interesting I’ve read on this website.
    I really hope you have a follow-up to this coming up, hopefully showing some of the sewing techniques I haven’t yet been able to learn and practice. Sleeve-setting, with all of its complications, immediately comes to mind.

    On a side note, I know that in the tailoring world one must either learn by replicating the steps of his mentor, or by actually following a specialized course, but would you happen to have a particularly good book to recommend, to use as a guide for drawing up custom patterns? As a basically broke student who’s always been a self learner, I can’t afford tailoring (or pattern-making) school at the moment, but this has never stopped me before.

    I have relied on an updated edition of “The American Garment Cutter” that my grandmother (who was a seamstress) had in the basement, but it’s quite old (I think from the early 1900s) and I have found it difficult to follow at times.
    Please hit me up if you think of something, and great work on both the collection and the article!

  • GregS

    This is a great series, looking forward to the rest of it.

    Out of curiosity, are you planning on having others in the menswear community review your suits at any point? Not that I’m accusing you guys of being any less than forthcoming about your line (so far quite the opposite, in fact), and I suppose the MTM/bespoke angle makes a review even more subjective than it would otherwise be, but it’d be interesting to see truly independent perspectives on the process and product you’re creating.

  • n00b2000

    This is a great series, looking forward to the rest of it.

  • Jose Torres

    Interested to see how customisable your suits will be in regards to the lapels.

    • Dan Trepanier

      Thanks for your comment Jose. Our garments are all designed by yours truly, and won’t be offered with lapel customizations. Think of it like being designer menswear, but with a bespoke fitting process. More soon!

  • AdamE

    Really interesting piece, I think a lot of us are vaguely aware of the pattern-making process, but it’s neat to see the behind the scenes that goes on, once you leave the tailor shop and they get down to work… excited to see the evolution of this project and the final product…

    • Dan Trepanier

      Thanks Adam. We believe in educating our readers/clients and providing a much-needed level of transparency to the custom menswear business. We’ll also be sharing more on the specifics of pattern-making as it relates to adjustments for unique body types in future content. Please stay tuned. Cheers.

  • guest

    Hey Dan, would you recommend the FIT menswear program for someone who’s interested in pursuing menswear fashion design at some point and also needs a generalist overview of the industry?

    I already have a BA but in a field I’m no longer interested in, and recently realized that the FIT program is actually only 2 years and is very affordable for in-state students.

    Trying to weigh my options between the menswear AAS and taking independent workshops, certificate/credit/non-credit courses, etc.

    • Guessst

      The two year program at FIT is ok, but you need to ask yourself if you only want to do it because bloggers have made clothing, and working in the industry “cool” the apparel industry is an extremely tough industry to break into, and out of all the people who work in the field, only a small percentage achieve any notoriety. I don’t want to dissuade you, but do you want to make it your new life and career, or is a hobby?

      Best of luck from a student finishing up his four year BS merchandising/ design.

      • Dan Trepanier

        Hmmm. I think it’s always good to study something that you are passionate about – whether that’s in a formal school program or on your own terms with self-learning and mentor relationships. With the job market and industry landscape changing as fast as it is, it’s hard to predict how career moves will be made in the future. If you are truly passionate about something, I think you should learn as much about it as you can… That’s the key to (eventually) finding a job (or hobby) that brings you satisfaction, fulfillment and excitement.

        I get a lot of messages from young guys who are apprehensive about studying what truly interests them, and instead pressure themselves to stick to markets that, on paper, show the best potential for stable careers. I understand the need for security and stable finances, but it wouldn’t be my choice, lifestyle wise. The happiest people I know spend their days doing what they love…even though many of them don’t have a ton of savings.

        Just my two cents. I’m no guidance counselor, but I think you should follow your heart.

        Cheers mate.

      • guest

        Thanks for the reply. Why do you say that the FIT program is only “ok”?

        Yeah, I’m definitely not one of the kids who saw a bunch of “sick fits” on the blogosphere and decided that I was going to be the next Tom Ford, Rick Owens or anything like that. It’s easy to get annoyed with all of the “lifestyle” brands that pop up all over kickstarter and the like with completely ordinary and non-interesting designs, fabrics, etc

        However, I’m also not quite sure that I agree with your dichotomy of “new life/career” vs “hobby”. The way I see it, is that learning these skills will be an investment for the future. Fashion and style are two large interests of mine, and there are countless people in the world who make money from what others would merely term hobbies. The internet makes it easier than ever to create an audience and bootstrap companies and products with low upfront and overhead costs.

    • Dan Trepanier

      Absolutely. I learned a TON in my two years there (although I did the program in combination with heading-up the measuring & fitting at MAB). It truly is a crash-course in all things related to tailoring and menswear production. You’ll also get a great overview of how the menswear industry churns, and how the different potential careers are related… Although, as a blogger documenting the shifts of the industry, it might be changing faster than the course load… Either way, a foundation is necesssary to develop expertise – whether that’s a great mentor, or a great program.

      Just remember, when there’s a will, there’s a way:

      • guest

        Appreciate the reply, Dan. Interesting that you say the industry may be changing faster than the courseload. Look forward to future commentary on that. But, I’m sure the the principles of classical design and tailoring, pattern-making, construction, etc will always be useful… like you say the foundation is necessary.

        re: Camillo Love -> Craftsmanship, demonstration of expertise, passion, unique designs, and novel ideas will always shine through. As the internet continues to be harnessed as an amazing leverage tool for new ideas and startup companies, it follows that differentiation from the pack may become more and more important. After all, there can only be so many “here are $90 14oz Cone Mills Denim in a slim-straight fit” companies to go around.. I’m always inspired by the stories of solitary craftsmen and designers who make a name for themselves.

  • Jon Yeazel

    Looking forward to seeing how this line plays out for you guys. I wouldn’t mind getting involved somehow if there is an option to do so.

  • Tom

    This is like when Kick-ass made his superhero costume out of spandex

    • Dan Trepanier

      Haha. Well, a sharply cut suit can make a man feel like he has super powers. Cheers Tom.

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