Essential skills: garment side seams

A wee bit of sewing know-how is handy in the outdoor realm.  And not just for fixing stuff, though that is a subject I will get to over the next month, but for the slightly more advanced (conceptually, if not always skills-wise) realm of modifying gear.  Today we will confine ourselves to the introductory topic of altering the torso size of jackets and vests by taking in and (bonus points!) expanding the side seams.

Garment fit is not a matter to be taken lightly.  Sub-optimal fit makes pieces less thermally efficient, less cohesive while layering, and more annoying (flapping in the wind. etc).  If you have a body type or fit preferences which fall outside the norm, your are generally stuck with either just getting by, or perhaps shopping around to find a company whose patterning might better suit you, a potentially protracted and expensive procedure which is by no means a sure thing.  Modifying garment fit is a surefire way to address this issue.   I don’t have this problem, as I generally fit just fine in anything labeled medium, though sleeve length and hood size are both often a bit lacking.  My favorite application of altering torso fit is, rather, to alter garments which aren’t my size that I have managed to purchase for cheap.  In either case techniques are the same.

For the past few months I’ve been exploring a Patagonia Stretch Terre Planing hoody as a replacement for my BD Alpine Start windshell.  The Terre has promise in this area, with one glaring flaw in the voluminous torso size.  Mid-waist circumference (in medium) is 3.5 inches more than the Alpine Start, which is itself on the generous side of something meant to go over a midlayer or two, but not allow too much heat loss via flappage.  The Terre is meant for ocean sports, and presumably the added volume is to fit over a kiteboarding harness, but given the otherwise excellent fit (long arms and torso, excellent hood) something needed to be done.  Thankfully the Terre has what most jackets and vest have; vertical seams up the center of each side right under the nadir of the underarm.

The mod is basic: measure (several times), do your math right, turn the jacket inside out, sew a vertical seam up parallel to each existing seam to take the desired amount in (taper up to the arm pit in the last ~2″), trim the excess (to a 1/2″ to 3/8″ seam allowance), singe the fabric edges, then turn the garment back right side out, fold the seam over, the fell (i.e. sew flat) parallel to your new seam to hold the excess in place and add strength.  The Terre fabric is thinnish and stretchy, with this later characteristic making stress on individual seam holes more acute as I’m sewing with non-stretch thread.  Felling the seam is a good call with such fabrics, or with fabrics like fleece who often don’t hold on to seams as well as more unified products.  The end result, shown at top, doesn’t need to be super pretty or exact, just straight enough, and tight.  Get the fit right and you’ll forget about the mod and go about your outdoor life.

Extra effort is in order when things like hem cinch cords have to be relocated.  If the cord tunnel goes all around the hem, you’ll have to pull that seam out, do the above, then resew the tunnel without sewing the cord into the seam or anything similarly silly.  In the case of the Terre to tunnel ended at the middle seam, so I felled it forward (towards the zipper) to make things easier.  I had to relocate the little anchor loop for the cord lock, something I put off until I was felling the seam.  With the seam locked in it was easy to just stuff a little fabric loop into the fell and triple pass along the way.

It is less probable that you’ll want to take a whole jacket in all the way up the sleeves, but the same procedure can in theory be used here.  It is more complex, as cuffs are usually more complicated to take apart and put back together, and sleeve patterning is less likely to feature a straight seam off which to benchmark.  I am much more likely to pin when taking in a sleeve, as the amount you’ll be reducing tends to vary, and the margin for error is far less (as a percentage of the whole).


Adding girth is more complicated, but possible via essentially the same process.  My favorite example is this early 90s ish Patagonia vest I found 2 years ago in a Butte thrift store for 50 cents.  It’s a small, and I while I could technically wear it function and style demanded it be big enough to layer over something like a heavy fleece.  The tricky parts were color matching the salmon fleece inside the collar (came close after 40 minutes in Joannes), splitting the sides in a non-messy way (the outer shell is some kind of monolithic poly WPB laminate, with ~80 grams/meter Polarguard and a taffeta liner), and dealing with the drawcord cinch around the arms holes.  In this case I sewed the whole sandwich of materials shut, then sewed the fleece strips to each before felling as mentioned above.  I punted on extending the cinch sleeves across the fleece panels, as that wasn’t really necessary to preserve function.  A nice bonus here is that a pair of jacket sleeves always has enough length to make side panel additions.  A few years ago I found a woman’s large Nano Air jacket for $10, older, but in very fine shape.  This one I could not really wear at all, so after a bit of playing around I cut off the sleeves, sewed the arm holes shut, and added 4″ wide panels to each side, giving me a functional vest for 10 bucks and 45 minutes of enjoyable futzing.

Most importantly, modifying (and repairing) things feels more satisfying in this transient, hyper-consumerist age.


3 responses to “Essential skills: garment side seams”

  1. Being tall I generally need an XL to get a good fit on sleeves and shoulders. I’ve often thought about buying a size up and doing the mod to bring in the torso, but it’s pretty painful to put scissors to something new! Extending pants with some fabric has also crossed my mind since most outdoor companies only make a 32″ inseam, but my wife would probably divorce me…

    1. Once you cut up the first brand new thing it gets easier.

  2. […] caveats.  The first and by far most significant downside is the torso volume, which as discussed here is positively huge for the size.  I don’t think I could live with the STP without modifying […]

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