DIY Alterations Tutorial: Slimming + shortening blazer jacket sleeves with lining

I haven’t been posting as much due to work and prepping for exam cramming, but follow me on Twitter for some fitting room photos and more. I’ve fallen very behind on emails and comments but will try to respond to any questions soon. Thank you for your patience!

On to today’s post ~ I used to sew and gave up due to lack of patience and skill, but felt inspired to dust off my sewing machine again. Here’s a little something that I worked on recently:

Which sleeve looks more flattering?


H&M; Blazer.  Left sleeve (on me) slimmed & shortened, right sleeve unaltered.

When I initially tried on this blazer, I almost left it behind. I loved the light gray material and slim torso, but did not love the lack of lapels, the much shorter back, and the unsightly wide and bunchy sleeves. My other gray cascade jacket had the same sleeve issue, but it was unexpectedly sold before I even considered alterations. My current tailor charges $25 for shortening sleeves, and $20 for slimming (hopefully less for both done together).


I’ve done simpler alterations in the past such as slimming shirts and taking in the waist on a skirt. Never had I worked on a blazer, and especially not one with lining. I gingerly took apart one sleeve and tried to learn by retracing the steps of how it was assembled. As you can see in the above pics, such an alteration can make a tremendous difference in the overall silhouette of a garment.


I think I got the hang of it after one sleeve, and took step-by-step photos the second time around. Warning: Please note that I am an amateur and I’m sure there are better and more efficient ways to do this. The remainder of this post is picture-heavy and sleeve-focused so continue scrolling at your own risk of dozing off…

How To Alter Blazer Sleeves

1. If you’re not an experienced sewer, start with an inexpensive blazer that you won’t weep over if you accidentally slice or botch it. Turn the blazer inside out and use a seam ripper or sharp scissors to take apart a few inches of the lining seam (enough for your hand to fit inside comfortably). Make this hole about a few inches above the sleeve opening.


2. If you are only slimming the sleeves, then the side hole made in step 1 is all you need. If you are also shortening the sleeve length or only shortening the sleeve length, then take apart the seams connecting the lining to the outer material.


3. While the blazer is still inside-out, push the sleeve lining up near the shoulders and out of your way.


4. Measure a blazer that fits you well, and mark the one being altered with fabric chalk. Note that sleeves should not be the same width from top to bottom. It should be wider at the armpit opening and taper down by the wrist. I marked the following using a Theory blazer as a guide: 5.5″ across by the armpit, 4.5″ across by the elbow, and 4″ across at the wrist opening.


5. Use a rule or straight edge to draw a fluid line, then pin. I hate using pins and always stab myself, but they serve to keep the two layers of fabric from moving around.


6. SEW in a uniform stitch along the chalked/pinned line. Remove pins before they get near the machine.

7. Trim off the excess leaving about half an inch beyond the stitch, otherwise the extra material could look bulky. If you have a serger, you can use it now to prevent the raw edges from fraying, or do a zig zag stitch on a regular sewing machine.


8. Iron down the freshly trimmed edges from the inside and then also from the outside. Ironing is critical to sewing. If this seam was not ironed down, then it will not look crisp and smooth from the outside.


9. Measure out your ideal sleeve length, trim then fold down the material, and iron to keep it in place.


10. Pull the lining back down and trim off the extra length as well. Leave about an inch of length between lining and the end of the sleeve, fold the lining under, and then iron to keep in place.


11. Now our sleeve and lining are ready to be joined. This was the trickiest step for me. Using one hand, go THROUGH the hole we created in step #1 to carefully pin the edge of the lining and the raw edge of the outer material together. Make sure the pin is not poking through the inner lining NOR the outer material.


You can see my pins through the lining. Do this going all around the wrist opening.


12. I have no idea how to clearly describe this next step. Insert your hand again through the hole created in step #1, and pull the raw edges of the outer + lining (should be pinned together) THROUGH the hole.


13. After you pull the entire wrist through the little side hole, it should make a full circle. Sew along the pins.


14. After you’re done sewing around the circumference of the sleeve opening, insert the end of the sleeve back through the side opening, so it’s back to normal. Steps 9-13 are how I joined the lining to the sleeve without any visible stitching from the outside.


15. Now, try on your blazer. Re-do the sleeve width or length if necessary, always ironing it smooth afterwards. Once you are satisfied with the alterations, we can close the little lining hole made in step 1. At this point I was too tired to learn an invisible stitch, so I just used pink thread and stitched the lining shut from the outside.


16. Lastly, (optional) I secured the sleeve length with a light hand stitch using the same colored thread.


All done! Phew! I will show the completed garment soon.
Readers – Do you do your own alterations? If so, please share some tips or links to good tutorials.

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  1. Just a little tip

    Put the pins the oppeside way, so they are crossing the way you sew, instead of the same way you sew, then you don't have to pull them out, you can just sew over them 🙂

    Posted 2.2.16 Reply
  2. Anonymous wrote:

    If you're just slimming the sleeves you said that you just need the side hole in step 1. Can you show how you would continue with the alteration?

    Posted 10.24.14 Reply
  3. Anonymous wrote:

    great post! can you do tutorial for altering the sleeves of a leather?

    Posted 2.2.14 Reply
  4. Anonymous wrote:

    wow.. this is amazing. great work!

    Posted 1.28.14 Reply
  5. Anonymous wrote:

    Washing and drying clothes aren't rocket science. I'll tell you what you should do if you want to extend the life of your 'going out clothes' or your entire wardrobe. But of course, you need to get your hands 'dirty'! Never rely on others (maid/family members) to do your washing for you lest your clothes be ruined.
    FOR REALLY DELICATE OR EXPPENSIVE THREADS OR LINGERIE(eg;a knitted top you don't wanna grow out of shape or a slouchy cotton top,etc):-
    1) Separate them in terms of colours. Whites, creams, or any light pastel colours to one side. Black,navy,gray to one side. Limit the number of pieces in each group. Don't wash everything at one go unless you have a really big laundry room where wet floors are allowed or toilet space.
    2) Turn the clothings inside out.
    3) Pre-treat any pieces with stains first using Vanish, Chlorox(for white clothings) or any of your desired brands. If you're using Chlorox on a white piece, then do not mix it with coloured clothings even if it's light or pastel hues.
    4) Place the clothings inside a large tub or pail.
    5) Fill large pail or tub with liquid/powdered detergent and let the tap water run at the same time. You'd get a tub of foamy water at this point.
    6) Leave it to soak for just 10 mins for unheavily soiled clothings.
    7) Time to get your hands dirty; err soapy..haha .Dunk your hands into the foamy water and raise each piece up using rubbing motions on certain stained areas that need thorough cleaning. Dunk and raise until you are satisfied.
    8) Ever so gently wring the excess water out of each piece and transfer the wringed pieces into the toilet sink or a an empty pail.
    (You should not wring vigorously on woollen or knitted ones OR LINGERIE.)
    9) If it's a sink, let the tap water run on to the clothings. Remember you can control the amount of water used. This is where you rinse off the clothings. Rinse till no more foam comes out. If it's in an empty tub, just fill the tub with water and repeat the raise and dunk process.Drain the water and refill with clean water again. REpeat till it's no longer foamy. This, to me is a bit of a wastage. I prefer the sink method.
    10) Now at this point your clothings are clean. Once again wring ever so gently, and put it back to shape using hangers. Your clothings are damp and still soaked with some excess water. Hang them and wring on certain areas where you deem needed.
    11) Leave them for an hour or longer. Depending on the material, some clothings take a shorter time especially if there's plenty of surrounding air or just because it's a thin material like chiffon or polyester.
    12) Sun dry them outside or at the usual area where you would hang them to fully dry. At this point, you should make sure no more excess water drips.
    13) Voila! Wait a day or two to collect your clean laundry!

    1) Adjust your washing machine to Delicate or Light Wash option. If there's none, just adjust the Washing , Rinsing , and Drying/Spinning to the lowest or minimum timing.
    2) Run the machine.
    3) Wait till it's done.
    4) Hang to dry. Use hangers preferably to keep in good shape.
    5) You're done!

    Source: I do this for my own clothings and lingeries included. I don't mix my washing with my family members' eversince my batch of going out clothes (mind you they are Topshop,Zara, Mango,Bershka items) expanded and even ruined by a colour run of a family member's clothing! Horror!! . Lesson Learnt!

    Hope this is helpful!

    Posted 11.16.13 Reply
  6. Lu wrote:

    Well done! I like so much your blog!!!!! Congratulations!

    Posted 8.19.13 Reply
  7. Anonymous wrote:

    I bought this exact blazer in this color and in black yesterday in a size 4! They fit perfectly, but the sleeves are just a tad short: they show a bit of my wrists. Do you think this is acceptable? Or should I try to take them to a tailor to have them lengthened somehow closer to my hands?

    Posted 8.10.13 Reply
  8. Anonymous wrote:

    Great tutorial. Arent you supposed to pin 90degrees from the seams rather than running alongside the seam? then you can also sew over the pins with sewing machine and remove them later and they dont get stuck under the machine foot.

    Posted 7.27.13 Reply
  9. Anonymous wrote:

    Potong Pasir MRT at the doorstep, residents can easily
    access almost to any destination through.the interlace condo

    Posted 6.7.13 Reply
  10. Anonymous wrote:

    new reader! awesome DIY tips for me as i'm also petite and sometimes having trouble fitting in clothes!

    Posted 5.24.13 Reply
  11. Khiara wrote:

    I saw your blog and decided to try the tutorial myself as I have two suit jackets that swim on me around the arms! I'm so so happy with the results! I don't sew very often but know the basics, I found it quite easy and had one jacket done in about 30 minutes! I'm on to my second jacket now but thank you so much for the post and saving me a heaps of money from getting it professionally altered. Now I'm browsing through your other posts to see what else I can improve in my wardrobe!

    Posted 3.24.13 Reply
  12. Anonymous wrote:

    I'm looking to get a sewing machine. May I ask what model/brand you are using? Thanks for sharing your tutorials!

    Posted 3.2.13 Reply
  13. Karen wrote:

    I just stumbled upon your blog looking for a specific type of alteration. I sew quite a bit and I am refreshed by your approach! It may be unconventional but apparently works very well! I think it's great to post them because it will free up many non or beginner sewers to just give it a whirl and lo and behold, it might just work. Especially great that you thrift so you allow others to try this out on inexpensive finds. Cheers and good posting!

    Posted 2.18.13 Reply
  14. Anonymous wrote:

    Oh I love this! You have inspired me to learn how to do these kind of things! Keep up the good work!

    Posted 10.29.12 Reply
  15. Anonymous wrote:

    Thank you Thank you Thank you. This gives me some courage to alter my coat sleeves. Thanks a lot. Love your tutorials and you are a great teacher.

    Posted 7.31.12 Reply
  16. Thifa wrote:

    I just don't understand where the second trimmed part (step 8) come from. Otherwise, I love this post! I'm always coming back to it for inspiration 🙂

    Posted 3.2.12 Reply
  17. I love that idea!

    Posted 2.11.12 Reply
  18. Rach wrote:

    hi Jean, would you be able to recommend a sewing machine for projects such as this?

    Posted 1.30.12 Reply
  19. I slim sleeves and torsos down all the time too (I'm 5'2" and a slim 0P)! A trick I learned from my mom is that instead of pinning the sleeves along the chalk lines and having to take them out again before the machine, you can pin the sleeves perpendicular to the line and the machine's needle will just go right over it! Definitely saves some time. Great job, Jean! Your blazer looks so much better! 🙂

    Posted 1.29.12 Reply
  20. Thanks for the guide I could've used this when I took in and shorten a blazers sleeve a few months ago. But this helps for future DIY projects thanks again.

    Posted 1.19.12 Reply
  21. Midori wrote:

    jean this is amazing. if i ever figure out how to sew in a straight line (i'm hideously and embarrassingly sewing-machine challenged) i will give this a try on a cheap-ish jacket.

    Posted 1.16.12 Reply
  22. Monkey wrote:

    That's wonderful!! I have a blazer that's been languishing in my closet for years because the sleeves are too wide. I can't wait to try this myself. Thank you thank you!

    Posted 1.16.12 Reply
  23. Paula T wrote:

    You are right, his makes such a difference, I do the same sometimes. I picked up a beautiful vintage silk summer jacket in London a few months ago and it just wasn't right on my shoulders (I have narrow shoulders) So after a quick nip and tuck it was perfect. I didn't trim off the excess though so that I could pass on to others with less ridiculously small shoulders in the future once I've finished with it 🙂

    Posted 1.15.12 Reply
  24. The pants here are Gap legging jeans ordered online, in size 00 Petite. They are from a year or two ago though and the current petite length feels too short for me (and I'm only five feet tall). I don't know how tall you are but they carry regular lengths in store starting in size 24 / 00, which runs pretty small.

    Posted 1.14.12 Reply
  25. THank you! Great site.

    Posted 1.14.12 Reply
  26. I left that point untouched…I didn't want it to look awkward or bunchy at the armpit so I just gradually made the sleeve slimmer while starting out at the original width by the armpit. I stopped trimming off the excess about 2-3 inches before the armpit area.

    Posted 1.14.12 Reply
  27. Megan – I tried my best to show it in the photos but I know it's not clear at all : / I don't know if I'm doing that step right because it seemed so tricky to me, but it was the only way I could figure out how to make that stitch not visible from the outside. Maybe if you search around the internet for sleeve shortening alterations, or on YouTube, some better tutorials will come up.

    Posted 1.14.12 Reply
  28. Hi Janki! I'm happy you've found some of my posts to be helpful : ) As for sleeve and pant hem length, it really is personal preference. I like my sleeves to end about one inch higher than the base of my thumb, whereas some like it closer to the wristbone. For non-skinny pants, I try them on with the shoes I'd be wearing the most (so go with your work heels if that's what you wear) and I like my pants to be about an inch above the ground. I hate dragging pants. Some women though like it closer to the ground so the leg lines are as long and lean as possible.

    Posted 1.14.12 Reply
  29. Hi there – My bad memory is preventing me from remembering which silk blouse this might be. I don't think I've ever altered one myself because I only work on "cheap" items in case I mess up. Let me know if you can find the post or exact item : )

    Posted 1.14.12 Reply
  30. Great tip, thank you. I knew I needed some interfacing but was too lazy to find a JoAnns : / Will be sure to pick some up going forward for random projects.

    Posted 1.14.12 Reply
  31. Meg wrote:

    What an amazing difference! Thanks for the tutorial — I'm not sure I have the guts, but it is great to see how you did it. The only two things I can add are 1. Use pinking shears to cut the excess off and it will save the trouble of serging or zig-zagging, especially if the piece is lined and that seam won't be getting any direct wear and 2. Press the seam with both selvedges together first to "set" the seam, and then press it open. It gives a really clean finish.

    Posted 1.13.12 Reply
  32. Anonymous wrote:

    i have been following you for some months and i absolutely adore your fashion sense!!!
    i always have hard time finding pants, and i love how this pants fit you (at least whatever i can see)…where are they from? thank you

    Posted 1.13.12 Reply
  33. Anonymous wrote:

    I really like the extensive alterations tutorials that are on the sew for dough website:

    Posted 1.13.12 Reply
  34. xJOLE wrote:

    Oh my goodness this looks insanely complicated! Amazing job, though.

    Posted 1.13.12 Reply
  35. al2ice wrote:

    This is incredible! Your pictures and explanation made me think I can really try this myself. Just need the patience and finesse, oh and a sewing machine! 🙂 You are very TALENTED! Thank you very much for the instructions.

    Posted 1.13.12 Reply
  36. Anonymous wrote:

    Great tutorial! I always make my own alterations and the easiest I've ever done is a couple of darts in the back of a pencil skirt — it helps when the skirt isn't fitting quite right.

    Posted 1.13.12 Reply
  37. Jude wrote:

    Nice! I doubt I could give you any advice as far as sewing, but the way you place your pins is different from the way I was taught. I place my pins perpendicular to the seam to be sewn and then trim the excess fabric after the sewing is done. The perpendicular placement allows the sewing needle to run over the needles without having to stop the machine and pull out each needle. I figure this is a six one way, half a dozen another tip. Either way the job gets done. : )

    Posted 1.13.12 Reply
  38. Anonymous wrote:

    You're so talented, Jean. Amazing!

    (another, but not-so-talented) Jean from Singapore

    Posted 1.13.12 Reply
  39. Katie wrote:

    wow, good job, for a self-confessed amateur!!

    Katie x

    Posted 1.13.12 Reply
  40. Best of luck to you! I am on level 3 but haven't started yet, and I think time is running out for this year : ( It's extremely tough to do it while working long hours, but after you finish it's an amazing feeling of accomplishment. Don't kill yourself doing it, though – it's not worth it! I was feeling emotionally and physically unwell last year after working those hours and studying each night, and I'm trying to avoid that for level 3.

    Posted 1.13.12 Reply
  41. I took lessons as a teen but they didn't cover a lot. I think lessons are key when you're just starting out, otherwise I wouldn't even know how to thread a sewing machine. After some basic lessons, you can self-teach by following tutorials or trying to retrace manufacturing steps like I did here.

    Posted 1.13.12 Reply
  42. Hi! It's Essie Hot Coco.

    Posted 1.13.12 Reply
  43. Kim wrote:

    Great job! It looks professionally tailored! Love the jacket as well!


    Posted 1.12.12 Reply
  44. Anonymous wrote:

    Very cool – you are very talented. I have a question, what happens to the point where the sleeve joins the jacket (armpit area)? Once you trim off the access width wouldn't there be hole at the connection point?

    Posted 1.12.12 Reply
  45. How do you magically always post something at the right time for me?? 🙂 I recently re-discovered a lovely BCBG Maxazria blazer that my mom had found for me at Marshall's waaaaay back, and remembered that the sleeves were way too long. I'm a bit of a DIYer myself but too lazy and confused to figure out some things, like how to reattach the lining again. Your strategy looks great and I will hopefully try it out soon. Your comment about your sewing skills is totally not true–you definitely have sewing talent!!

    Posted 1.12.12 Reply
  46. Anonymous wrote:

    Or you can just live in Mexico where I do. Relatively cheaper tailoring! 🙂 –April

    Posted 1.12.12 Reply

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