Adjusting Big Jumpers for Small Blokes: Tutorial

My ex was an XL with a taste in expensive cashmere office-hipster jumpers. I've had a sack of his offcasts for years now: attempting to resize one was my first, disastrous sewing outing. I have a lot more experience now and, three years on, have successfully adjusted the jumpers. Win!

This is what you do.

(NB: this is a fairly challenging project. Start with charity-shop crap, and practice before using on something you like. I've made the instructions as clear as I can, but some of it is just a knack for handling tricky fabrics and understanding clothing shapes. Really, this is more of a record of what I did so I can consult it in future - I'm not a great tailor, I promise no results.)

YOU WILL NEED

• An oversized jumper.
• Good thread in a matching colour (ie Gutermann)
• Two threads in contrasting colours (any quality)
• Fabric scissors
• Embroidery scissors/snips
• A sewing machine OR confident, strong hand-sewing and a bunch of time.
• Tailor's chalk 
• Pins - choose ones with brightly coloured heads, easy to see in the wool
• Regular sewing needle

YOUR JUMPER 

This is a tricky tutorial, and I am an inexperienced teacher: I'm making notes of what I did that worked, rather than telling you something which will definitely work.

Start with a cheap or nasty jumper; pls don't start with your granddad's jumper from the war.

The bigger it is, the easier it will be to adjust: more room for adjustments and fine tuning. If it's just a few cm off, then it's better to live with it - jumpers being a baggy garment after all! If you're at the charity shop, choose the biggest sizes you can find.

You want a jumper with a shoulder seam exactly on the shoulder: not a yoke or raglan sleeve. Fewer patterns and textures the better.

ON FABRIC

Jumpers are made from stretchy fabric - jersey, wool, or some sort of blend. This makes them annoying to work with, and not ideal for a beginner. If you can, try the tutorial with a rubbish jumper before adapting a nice one.

Pick up a piece of paper. Put it down. Waft it around. Lay it on your knee. The paper moves, BUT it does not stretch: it remains solid. Remember this paper when working with the jumper. Handle it gently, like a piece of light paper. Don't push, force or tug it, or stretch it out on the table, or let it dangle so the weight is in the air. All of these things allow the fabric to stretch. Let it just sit naturally. When you need to match a seam to a seam, imagine you were airing out a duvet: lift a whole area of the jumper and then place it back down - instead of just tugging the seam to match its twin. The fabric will let you do it, but it'll distort when you sew.

Pin more than you think you need to. Pin perpedicular to the seam. 

Use a walking foot and a zig zag stitch if you can. I didn't have either, so I did two runs of regular straight stitch on each seam and it was ok. If you're handstitching, use backstitch. More sweater advice. In fact that blog's just plain great: there are additional steps you can take to prevent fabric unravelling/distorting in preparation for cutting; and for using elastic on seams; and for understanding parts of jumpers under the most strain, and how to strengthen them.

To finish the seams, you can trim to 1.5cm and run them with the zig zag stitch; or use this Hong Kong finish; or overcast by hand; or get an overedge foot; or a serger, which is how they do it professionally.

This additional tutorial shows how to add a piece of rib to a sweater - ribbing is generally used for cuffs and lower hems. You may, in some rare circumstances, wish to remove the cuff and hem and then re-attach them, as part of the adjusting process.

PLANNING

Measure twice, cut once: this is our watchword.

0) Put on the jumper inside out. Stand in front of a mirror.

Look for any awkward fashion details. This tutorial assumes your jumper has an arm seam on the shoulder point (it's not off-the-shoulder or raglan), a shoulder seam at the top of the shoulder (it's not a yoke) and so on. If your jumper has unusual features, be ready to use your initiative.





1) Shoulders

Begin by finding the top line of your shoulders. Pinch the jumper together and pull upwards, away from the body. Place a pin to show how much fabric you need to get rid of. Look at the neckline, and see that it comes to the right place on your chest (fig 1)

Figure 1: pinch and pin excess shoulder

 

Take the jumper off. Lay flat. Measure the distance between the shoulder seam and the pin - marked "x" in fig 2. Pin a line parallel to the shoulder seam. Now repeat this step on the other shoulder. This way, both seams will match. 

 







Figure 2: new seam, parallel





Turn the jumper the right way around. Try on. If you are happy, leave this and move to the next step.

On my jumper, x equalled 1in. This step fits the neckline, helps reduce the armhole size, and makes the garment shorter.



2) Sides Turn the jumper the wrong way around. Try on. 

Pinch the side seam just under the arm. Place a pin. Keep doing this all the way down one side. You will likely find the hip fits OK - don't make this too tight.

Figure 3: pinning the arm and chest 

 

Observations:
1) Menswear is baggy. It is not skintight. Socialisation may be telling you that skintight is better. Let it have some ease - especially for casual style jumpers, which are a loose garment.
2) but not too much ease! You still don't want it to look baggy. Don't fall into the trap of trying to hide your shape - it won't help you pass, it'll just look odd. Resist the temptation. In particular, you want the chest to fit fairly snugly so as to have a nice armhole.
3) you will probably find your side seams curving as in fig 3.

On my jumper, I reduced by 4in at each side of the chest, and zero at the hip.

3) Arms. 

Turn the jumper the wrong way around. Try on.

Pin the cuffs so they are comfortable. Pin the underarm so it is comfortable. Now, shift the sleeve so the cuff covers the wrist. Calculate how much you need to shorten the sleeve by.

Having the side seam and arm seam pinned simultaneously will make it fit oddly. Keep focusing on the small part you are fitting at the time.

4) Matching

Take off the jumper. Turn wrong way around. You should have one arm and one side pinned. 

Fold neatly in half, like a book from left to right. Pin the opposite side, by peeping under the top layer, and placing pins in identical locations, one at a time. Fig 5 shows the two sleeves on top of each other, with one pulled away so the pin positions can be matched.

Figure 5: comparing the markings

5) Testing + measuring

Look at the inside-out jumper. Check that it seems to be symmetrical. Turn right way around and try on. Make any adjustments on both sides. Keep tweaking until you are happy. Remember, jumpers should be loose-fitting - but not baggy. 

If you have a well-fitting jumper, you can measure it and compare it to the new jumper.

Fig 4 shows the inside out jumper and the lines of pins as green dashed lines. The orange arrows show where on the jumper is equal to what measurements on the body. If you measure your bicep, and add 2in for ease, then the number should be close to the bicep line shown on the diagram.

Figure 4: measurements and seam lines

5b) Bonus!

If you're comfortable flat-pattern drafting, you can also flat-draft a jumper pattern, dismantle the jumper, and use its pieces as fabric with the pieces. I prefer pinning, because it's more sequential, and because I'd rather be making things than using drafting as an excuse to not finish a project.

SEW THE SHOULDERS

6) Cut off arms

Turn the jumper wrong way around. Find the arm seam. Look at Fig 6 for cutting line.

Figure 6: you probably want to shorten the sleeves, so this is the best spot to remove the arms.

Make a snip, insert one blade of the scissor inside, and carefully cut as close to the seam as possible. Don't cut off the front and the back of the arm with the same cuts - the sleevehole isn't symmetrical! Carefully cut inside the whole circle (fig 7).

Figure 7: removing the arm correctly

Cut off one sleeve, and pin a piece of paper to it reading either LEFT or RIGHT. Now repeat with the other sleeve. 

7) Time for a cuppa

Don't panic!

8) Re-check fit.

Put the jumper on, right way around. With the arms, and the bulk of pinned fabric at the underarm, out of the way you may wish to tweak a bit more. Whatever you do on the left side, repeat on the right. 

8) Handsew shoulder details

Your shoulder seam should already be pinned. With the jumper the right way around, take your correct colour thread. Most jumper necklines have a pattern or detail. Use ladder stitch to carefully sew the neckline together, matching any stripes, and especially matching the edge of the fabric. Take your time. You want any lines, details, patterns and the finished edges of the garment to meet correctly. 

9) Machine-sew shoulder seam.

Once you have hand-sewn any details so they match, turn jumper inside out. Machine stitch along your pinned line. Try on. If you are happy, cut the original shoulder seam open and lay each side flat (fig 8). This prevents things getting too bulky.

Figure 8: lay the seams open

10 & 11) Repeat on the other side. 

DRAW THE ARMSCYE

The armscye is the armhole, and something of a fine art. Put the jumper on correct way around, straighten it so it sits well on your shoulders, and ensure you are happy with the side seam location. Take your chalk.

12) Find the shoulder point

Your shoulder bone is a knobbly bit around 4-5in away from your neck. Mark this with chalk. Take off the jumper. Use your marking thread to sew three or four times on the spot of the shoulder point, or sew a small cross. Measure the distance from neckline to shoulder-point down the shoulder seam line. Use this measurement to make a mark on the other shoulder, again in thread. Try on. Check it hits the shoulder bone well on both sides. 

The shoulder point is a crucial sexy fit location. Formal, elegant sleeves always have to find their apex here - unless it is deliberately off the shoulder. 

13) Draw the armscye

You already know where your underarm point at the bottom of the armscye is, and the shoulder point at the top. With the jumper on, eyeball a curved line between them. Sketch a dashed line with the chalk. Turn around and do the same behind. You probably won't get it right, so have a second go redrawing any dashes which looked wrong. 

Fig 8 shows our model topless. His shoulder point is marked with a red cross. The human chest naturally has a crease pointing upwards towards the shoulder point. The armscye should follow this line, shown in green dashes on his left side. Armscyes generally don't look curved when you're wearing a garment - they look straight, so be cautious of making the curve too pronounced. Finally, you can use the original arm-seam of the jumper for help. You're just shrinking the jumper, not changing its proportions - so if your shoulder point is 2in further up from the original shoulder point, you might try drawing a line parallel to the original arm-seam with the jumper taken off. This might give you a starting point for getting the shape correct.

Figure 8: location of the armscye on a naked bod

If you've ever made a basic bodice/shirt block, you can trace the armscye off that block onto your jumper for a head start. 

14) Mark the armscye

Take the jumper off. Take your marking thread. Baste along the chalk line you just drew to make it more visible. Try on. Repeat this step until the armscye looks good to you.

My armscye is usually around 43cm. If yours is very different, it might be a sign that yours is wrong.

Note we have only done ONE armscye at the moment.

15) Mark the side seams

Take your marking thread, and baste along the pinned line on both sides. Now, cut the side seams open - exactly on the seam. Take your time. Once you have done this, get embroidery scissors/thread snips and snip open the basted stitches - again, going slowly and holding the seam together with your hands, so the thread doesn't pull loose. 

Open out the jumper. The basted marks should provide a vague guide to where you will stitch the side seams!

(This is a new technique I figured out while making this jumper, and I'm delighted. Previously, I've either used fabric felt tips - which fade too quickly for long projects, and don't show on many fabrics - or tailor's chalk - hard to make smooth lines without distorting the fabric. But thread is made for this medium, and a bright contrasting basted stitch line takes moments to do, lasts forever, and is very precice. Game changer.)

ARM TIME

16) Mark arm center line on both sleeves

Fold the sleeve in half, so the arm seam is on one side. Now, use your marking thread to baste up the other side of the arm, right on the crease. Keep checking the arm is folded exactly in half - mine kept slipping out of place, and I had to roll it back. This line will mark the centerline of the arm.

use a contrasting colour to run a line of stitching along the fold, to mark the halfway line.

17) Fix length on one sleeve

Put the sleeve on. Seat the cuff in a nice place on your wrist. With the fingers holding the sleeve in place, find the shoulder bone. The underarm seam should be under your armpit, and the centerline of the arm should be sitting on the shoulder point. Get a pin, and place it where the centerline and your shoulderpoint meet. Now, with marking thread - do several stitches on the spot or stitch a small cross so you can find this point easily. 

18) Cut open the sleeve seam on both sleeves

Baste along the pinned line with your marking thread. Cut right along the seam. Go slow and be neat as you can. Now snip open the baste stitches.

Fig 9 shows the opened sleeve. The blue line is our marked center line. The red cross is our marked shoulder point.

Figure 9: marks on the sleeve.

 

18) Find under-arm points on one sleeve

On the original jumper, the sleeve fitted the armscye exactly. By reducing the size of the side, we also reduce the size of the armscye by a predictable amount.

 

Get the jumper. Measure from the underarm, up and around the armscye - curving your measuring tape until you reach your line of pins. Shown in fig 10. Remember that number.

Figure 10: left, marking measurement on arm; right, finding the measurement on the jumper body.

Take the sleeve. Measure an inch down. Now, measure distance y, parallel to the curve of the armscye. Mark this point. Do the same on the opposite side of the sleeve. 

19) Sleeve Complete

Fig 11 shows the completed sleeve. You have marked the centre line in your marking thread. You have found the shoulder point and two armhole points. The marking thread shows the line which was pinned: this should be a straight line from armhole-point to the start of the cuff.

To check fit: 

• Check the line between the armhole points is larger than [your bicep + 2in]. 
• Check the wrist width is satisfactory. This part of the garment is probably stretchy, so expect it to be less than your real wrist.
• Check the line between the shoulder point and the end of the cuff: this will be the length.

Transfer all markings to the second sleeve. Don't assume they are the same length: knit fabrics stretch over time or change shape in the wash. Measure the length of your first sleeve, from cuff to shoulder point; and measure again, from cuff, to find the shoulder point on the second sleeve.

SETTING THE SLEEVE

20) Transfer armscye markings

Currently, only one armscye has a sewing line. Place the jumper in front of you on the table, the correct way up (i.e. lower hem at the bottom, neck and shoulder seams at the top. Fold the jumper vertically, left to right - like a book.

Use the peeping and pinning method to accurately pin an identical armscye on the other arm. Then, mark it with the marking thread. 

21) Get a friend/mannequin/a pillow

Put the jumper on the table, right side up. Take the correct sleeve (i.e. right hand sleeve for the right hand armscye). Place it on top of the jumper, right sides together. Pin the shoulder point to the shoulder point. Pin the underarm point of the sleeve to the jumper at the front. the underarm point of the sleeve to the jumper at the back. 

Pick up the jumper, and have a friend or mannequin put it on, the right way around. Ensure it sits well and naturally on the neckline and shoulder.

The sleeve is pinned to the armscye at 3 points. Take the double-thickness sleeve fabric between your fingers and thumb, and roll it to reveal more. Pull out the fabric, and start pinning it to the armscye line. Go slow. It should form a really satisfying, solid shape curving neatly and flat around the arm. If it bunches up or gathers, unpin and try again. 

Fig 12 shows the jumper on an orange mannequin. The under arm and shoulder point are pinned in place, but the rest of the sleeve hangs floppy. Starting from a pin, we roll a small amount of fabric forward until it lies on top of the armscye line - and pin.

Figure 12: pinning the sleeve in place to find its armscye line

 

22) Mark the armscye line on the sleeve

Remove the jumper from your model. Using your marking thread, baste the sleeve where it meets the armscye - along the line of the pins, right in the crease as we did in step 16.

23) Transfer armscye sleeve line

Place one sleeve atop the other. Use the peeping and pinning method to pin an identical armscye line on the second sleeve. Mark with marking thread.

24) Set sleeves

Pin the first sleeve into the armscye (right sides together). Match the shoulder point and under-arm points. Then, neatly match the armscye lines and pin with perpendicular pins - here's fig 17.

• Use more pins than you think you need. 
• Check there are no wrinkles, pleats, tucks, gathers, or anything other than flat pieces.
• Take care not to stretch or tug the fabric as you pin - hold the fabric so it is as inert as a piece of paper. 
• Keep an eye on the marker threads. A quick basted running stitch can sometimes tug the fabric and create little hills and valleys. If you spot this, snip the offending thread with embroidery scissors/snips, and let it lie flat again. 
• Pin and repin until it is perfect. 
• Ensure the leftover shoulder seam allowance is spread equally (fig 8)

25) Baste

With a second contrasting thread, sew a neat running stitch along the marked seam line. Use smaller stitches than for your marks, especially in parts of the curve where the fabric most wants to wrinkle. But this is not your final line, so it doesn't have to be perfect.

Put the jumper on, right way around - or look at the sleeve without trying it, to ensure both jumper and sleeve are flat and wrinkle free and nicely set.

 

26) Machine sew

Machine sew the sleeve into the armscye.

27-29) Repeat with other sleeve

30) Finish the seams

Check the section "On Fabric" for some suggestions. We want to do armsyce seams before sewing up the sides, as it will be easier to do it neatly at this stage - and it'll make the seam less bulky.

SEWING UP THE SIDES

31) Another cup of tea

Being "so close to finished" is when one makes mistakes.

32) Pin sides and arms

Turn jumper inside out. Lay flat. Match the original seams, so the front lies exactly ontop of the back. Keep checking and adjusting, that it is not wrinkled or stretched, and that the original seams meet naturally - without forcing, and without rolling.

Pin the sleeve-seam and side seam with perpendicular pins.

Sew.

33) Finish the seams

Again, as you choose.

34) Remove extra thread

Using a pin, and your embroidery scissors, snip/pull out any visible mark or basting thread.

LAUDATE DEO FINIS EST

This was what worked for me, at least. I'm currently writing a followup post on tackling jumpers with a yoke, and using shrinking/stretching methods to reshape pieces. I hope this gives you some pointers and helps you complete a similar project.