Seaming a Sweater Vest

I knew opening up to questions would likely bring up some good ones.  Here’s one from Peter in TX:

“I’m currently knitting my first piece of clothing, a sweater vest (as I didn’t want to have to deal with sleeves). I assume I block the front and back separately before I sew it all together. I knitted a swatch and have been obsessively checking my gauge during the knitting process.

Any tips about sewing it together properly?”

This is an EXCELLENT question, and one I’m sure many of us have had over the years, whether it’s our first garment or our 10th.  Seaming always seems to be one of the least favorite aspects of garment construction… we are so excited to knit, then when all is said and done, and we have to put it all together to make a completed garment, we tend to rush through it, or the garment pieces end up in a “to do” pile somewhere, never to be seen again.  So, without further ado… here is my reply and a semi-quick and dirty guide to seaming a sweater vest.

General Notes

Congrats on working up your first garment!  That’s a huge step in your knitting life.  A vest is a good start, as you learn shaping, picking up stitches for armhole and neck bands, and steeking if you are working a steeked vest pattern.  And I’m so PROUD that you have been obsessively checking gauge as you work!

Blocking – Now or Later?

Now, strictly speaking, you don’t really HAVE to block your pieces first before seaming, but it will make finishing work a bit easier if your stitches are set and lying appropriately (especially those pesky edge stitches).  Also, blocking to the schematic sizes exactly before seaming will ensure you avoid the frustration of having to make last minute adjustments while seaming.  If you do block before seaming, be sure that your edge stitches are lying flat and not curling under… as an object lesson, yesterday I was ‘practicing’ seaming for fun (good to keep the skills up) and had knitted a couple small swatches.  Didn’t block and then tried to seam.  While it could be done, it was a little frustrating making sure I was in the right spot for the seam.  Knitted two more swatches, steam-blocked, and they were a breeze to seam.  So yes, I would recommend blocking first, but strictly speaking you could get away without it, and just block the finished garment.

The Order of Finishing

Now, on to seaming… I’ll walk you through the process I use and that serves me fairly well. I use the same order for pretty much any top that I knit, so I always know where I am in the process. First off, the “order” of seaming for a sleeveless vest:

  1. Seam Left shoulder seam
  2. Seam Left side seam
  3. Seam Right shoulder seam
  4. Seam Right side seam
  5. Weave in ends (at this point you can also re-block, but it’s not necessary if you blocked the pieces properly beforehand.  Sometimes I do a light re-block, especially with wool, so that the woven-in ends stay put)
  6. Pour yourself a stiff one… you did it!

Now, on to the mechanics of seaming.  You’ll need the following materials:

  1. seaming yarn (should be the same as your vest, but if you have a different color in a similar weight and fiber content, that will actually work just fine);
  2. tapestry needle (I use the Clover bent-tip needles — the slightly bent tip makes getting into the places you need to be much easier);
  3. scissors to cut the yarn (I have a thing about breaking yarn… it annoys me, but do it if that’s your thing).
  4. If you’re really paranoid, you can use some coil-less safety pins to pin the garment together (I cheat and use locking stitch markers as pins in a pinch), but the method I’ll describe really doesn’t require pinning the garment!  Different story when doing set-in sleeves, though, so keep that in mind.

Horizontal Seams (seaming Stitch-to-stitch)

For this post, we will focus only on seaming STOCKINETTE stitch patterns; I’ll save seaming Garter Stitch, Seed Stitch, etc. for another day.

SHOULDERS:  We will work EACH shoulder SEPARATELY.  For ALL seaming you will want the RIGHT (public) sides facing up.  Place the sweater back and sweater front pieces together on your work space so that the shoulders line up, with the public side facing you.  Now, look at your knitting… you should be able to clearly see the “V’s” of the knitting, just under the bind-off rows.

To start, you will make a FIGURE 8 JOIN at the right side of the left shoulder seam figure-8-join(remember, the front of the vest is nearest you).  Thread the tapestry needle with your seaming yarn (make sure you have a good length to work with… I err on the side of caution and use about 3 times what I think the seam will actually need.  Beginning with the back of the shoulder, insert the tapestry needle under that large ‘loop’ in the bind off row (it’s that half-stitch area from binding off).  Then insert the needle under the same area on the shoulder front, then insert the needle again in the same spot on the back of the vest. Now you’re set up and ready to seam.  You’ll use this method to start the side seams as well, so it pays to learn it thoroughly!  Remember, here you are working between the selvedge edge stitch and the first full stitch on each piece.

Working the Horizontal Seam

Step 1: Bring your needle back to the first piece, insert it into the very hole you came out of with your yarn.

Step 2: Push the needle through and out the other side of the entire V stitch just below the horizontal-seambind off.  You want to catch the entire V of the stitch.  Be careful not to split the stitch!  You just want to go under the legs of the V.

Step 3: Move to the other piece, insert your needle into the very same hole that your yarn came out of before.

Step 4: Push the needle all the way through and out the other side of the entire V stitch just below that bind off.  Again, don’t split the stitch!  Go under the legs of the V.

Repeat Steps 1-4 for the length of your seam (in your case, the front shoulder (each side) will dictate how many stitches to work — you are working STITCH TO STITCH here).

Un-thread your tapestry needle, grab both ends of that seaming yarn and give it a tug (not too hard… don’t distort the stitches on the garment).  This creates a “California Closet” — the bound-off edges magically turn to the inside of your work, leaving a nice seam line!  Weave in your ends.

The key here is making sure that you are going under the legs of the stitch, and be mindful to go in and out of same holes.  If you look at the diagram you can see that properly worked, the seaming yarn (dark green) looks like a new row of knit stitches.

Now, when you’re ready for the Right Shoulder, turn the entire work 180°; the back of the vest will be closest to you, the front will be away from you.  Repeat as above with new seaming yarn.  (Note:  if you left yourself a really REALLY long tail for seaming, then you can use that for your seams — personally I don’t recommend that as pulling the seam tight seems to work better if you use separate yarn, unless I’m missing something).

While I’m rambling on about horizontal seams, let me just mention that you CAN just Kitchener stitch the shoulder if you left yourself live stitches to work with.  However, a Kitchener-grafted shoulder is not as stable as the method I’ve described above.  Remember that in sweater construction, the weight of the entire sweater is suspended from the shoulder seams, so that is an area you want some stability.

Vertical Seams (Row-to-Row)

Let’s break this one down a bit.  Since you’re doing a sweater vest, I will assume you have ribbing at the bottom of the garment.  We’ll begin there.

Seaming Ribbing

Begin as before, with a long length of seaming yarn (same yarn as the garment or a different but similar weight yarn… the seam will be invisible when complete).  Start with a FIGURE 8 JOIN at the bottom of sweater (see above).

Now, look at your ribbing carefully.  Will you be seaming Purl-to-Purl?  Knit-to-Knit?  Purl-to-Knit?  You’ll need to know this before proceeding.

Purl-to-Purl Ribbing Seam

When joining ribbing with a purl stitch at each edge, insert the yarn needle under the horizontal bar in the center of a knit stitch on each side in order to keep the pattern continuous.

Knit-to-Knit Ribbing Seam


When joining ribbing with a knit stitch at each edge, use the bottom loop of the purl stitch on one side and the top loop of the corresponding purl stitch on the other side.

Purl-to-Knit Ribbing Seam (or Knit-to-Purl, it’s all perspective)


When joining purl and knit stitch edges, skip knit stitch and join two purl stitches as at left.

The key trick here is picking up the BAR between the edge stitch and the knit or purl stitches.  This is the exact same technique you will use seaming the entire side seam.  When the seam is completed properly, you will again form a “California Closet” where the selvedge just folds in to the back of the work.

Invisible Vertical Seams (a.k.a. Mattress Stitch)

The technique for seaming row to row is pretty simple… you use the Mattress Stitch!  If you don’t know how to work this, or just need a refresher, let’s take a look:

mattress-stitchWe’re working with the horizontal bars between the first “real” stitch and the edge stitch.

Insert the yarn needle under the horizontal bar between the first and second stitches. Insert the needle into the corresponding bar on the other piece. Continue alternating from side to side.  Remember, you are working on the PUBLIC side of the work at all times during seaming; the opposite of sewing fabric garments!  Pick up one bar at a time working your way up the side seam.

NOTE:  If you find that one piece of the garment has a very few rows more or less than the other, you may want to ease the difference by skipping a bar here and there.  If you don’t discover that difference until you’re near the very end of the seam, it really is worth it to take the seam out, calculate the difference, and make a planned decision of where to pick up extra bars, or skip a bar.  Don’t skip more than 2 bars at a time, though… let’s not weaken the seam too much! 

Once you’ve seamed all the way up to the armhole, snip your yarn, leaving a long-enough tail to weave in.  Do the other shoulder and side seams.


When working the vertical seams, you will want to try to match the gauge of the garment you’ve knitted.  Also, every inch or so, you will want to gently, GENTLY, tighten the seaming as you go.  None of this ‘seam-to-the-end-then-yank’ business.  We want to avoid puckering, and if you wait to the end of the seam to pull, you’ll likely end up with a hot mess of puckering and need to take the seaming yarn out and start over.  Tighten just enough to pull the seam together neatly without distorting stitches.  Make tightening as you go a habit for vertical seams!

Weaving In

I’m not going to go into a rant about weaving ends here.  Suffice it to say that I HIGHLY encourage you to get very proficient at duplicate stitch weaving.  If you need to practice, then knit up a swatch and practice.  Even taking the time to get a contrasting color yarn to practice duplicate stitching in the middle of a swatch will make life sunny and rosy again.

Final Thoughts

Finishing work doesn’t have to be a chore.  Set aside some quiet time and do it all in one go.  It actually goes pretty quickly once you get the hang of it, and is very meditative and calming.  Just doing my little exercise yesterday (like the one below) was a very informative, fun and gratifying project all on its own.

And my eternal rant:  SWATCH and PRACTICE.  In fact, before tackling the seams of your garment, try the following exercise:

  1. Knit 4 stockinette swatches, about 4″x 4″ (10cm x 10cm).  Lightly block them with steam (no need to go whole-hog and wash them, though if you want to practice blocking, then by all means go right ahead and block and pin those puppies out to size, making sure the edges are FLAT).
  2. With Swatches #1 and #2, practice horizontal seaming along the bound-off edges.  If you aren’t getting it, before doing the yank, pick that seaming yarn out and start again.  Do it until it’s second nature.
  3. With Swatches #3 and #4, practice vertical seaming (mattress stitch), working row-to-row.  If at first you don’t succeed, rip out the seaming yarn and try again.  Practice makes perfect!
  4. Extra Credit: Knit 2 swatches in 2×2 rib, to the same standard size (4″ x 4″ or 10cm x 10cm).  Practice the figure 8 join and seaming the ribbing.  Change it up a little and make one of your swatches have a purl stitch to be seamed to a knit stitch.  No harm in swatching at all.  I keep scads of yarn lying around from old projects, or that was just dirt cheap and that I’d probably never use in a real garment, just for this very purpose… call it “practice yarn.”

I hope that answers your question, Peter.  And I hope this has been helpful to others struggling with finishing work.  Finishing your knitting cleanly and properly guarantees that the final garment will be something that you will be proud to wear in public (or to give to others), and you’ll have a huge sense of accomplishment.


I highly recommend Nancie Wiseman’s book, The Knitter’s Book of Finishing Techniques.  Pick it up if you don’t have a copy!  One note, however, in flipping through it the other day I notice that she doesn’t use the Figure 8 Join (at least I don’t recall seeing it).  DO use the Figure 8 Join — this evens up the edges of your knitting and you won’t need to futz around with it in the weaving in of ends to make the edges nice and even.  If you can’t find it in your LYS, you can order from Amazon!
The Knitters Book of Finishing Techniques

–Happy Knitting!


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