sewing with knits March 01 2012, 7 Comments
With thanks to and permission from the lovely Kelly Hogaboom I have decided to re-post this wonderful tutorial on sewing with knits. I have been getting many emails inquiring about this particular post and I don't like to disappoint our faithful sewists (seamstress, seamster, tailor). You may need to refer to this tutorial sooner than you think. (hmmmm, I wonder what that means?)
I promised a few people a little blog regarding sewing with knits; here goes. My daughter requested a shirt in “earthy” tones. I had just enough in my stash to make her one. The natural-colorway was from a piece of organic bamboo yardage given to me by a friend; the brown was from a 100% organic cotton t-shirt I thrift-ed (I used most of the shirt to make a headband for my mother). In both cases once I cut out the shirt pattern pieces I ended up with only a small portion scraps to compost. I love it that I use fabric so economically.
Kelly used the Tee for Two pattern available here: http://www.craftsy.com/pattern/sewing/Clothing/Tee-for-Two-Small-sizes/3910
Knits are tricky. So many sewists claim to “whip up a t-shirt on the serger” – but the truth is, for most of us it takes time to get proficient at knits, especially those with a high degree of stretch. Many home sewists don’t even own a serger (or they own one and don’t know how to use it). I hasten to add, a serger is not needed to make great knitwear. The following tutorial regards making a t-shirt on a sewing machine. It needs only a zig zag function to achieve good results (a width of 0.5 – 1.0 and a length of 3.0 was used for this shirt).
One of the best tricks I know to make t-shirt sewing go easier is to stabilize the seam allowances. This means “painting” a solution on the seam allowances and allowing them to dry. This solution ensures that the knit will not roll nor be sucked into the feed dogs of the machine. It’s not a necessary step to sewing with t-shirt knits, but one that makes things a lot easier. In addition to creating an easier sewing experience, I have found the stitch formed on stabilized knits “floats” on the fabric (instead of being pulled into it). Not all knits need this treatment (a sturdy or non-stretch knit may not), but for my slim-fit t-shirt with the very stretchy, soft bamboo it made the whole process easier.
To stabilize the seams you can either purchase a water soluble spray-on stabilizer or a stabilizer by the yard. If you choose the latter, you simply dissolve a small amount in water to create a solution then “paint” the edges of your pattern pieces (shown below in a moment). In this case, I am sewing with a 1/4″ seam allowance so I stabilized about 3/8″ on each seam.
Which seams do you have to stabilize? Those that will be travelling across the feed dogs of the machines. For this pattern, this means all edges except the sleeve and shirt hems (which remain unfinished). I stabilized the short ends of the neckband as well, given as a last step in this pattern the neckband edges have to be top stitched closed in a little rectangle and I figured, “Why not?”. The neckband in general does not need to be stabilized as it is rarely against the machine (when you attach the band it will be the shirt bodice that travels across the machine surface) and it needs to stretch quite a bit to perform its function (which is to “snap back” after sewing and bring the shirt edge in to hug the neck).
Here’s a little photo-explanation of stabilizing (click each photo for more information):
After you've stabilized your seam allowances, you must let the pattern pieces dry. Give it overnight or, if you’re in a hurry, carefully put the pieces in front of a heat source (don’t burn your house down!). When the seams are dry, they will have a stiff edge to them. They may even be a bit waffle-y. Don’t worry about that, as on the machine they will sew up beautifully. Here is an example of the texture change resultant from the stabilizing process. It’s a bit difficult to see but it’s obvious to the touch (the green thread is the tailor’s tacks I use for pattern markings):
Now we’re all ready to sew!
In the Tee for Two pattern, the first seams sewn are those of the sleeves to the front and back bodice. I chose to do Option B. of the pattern – that is, a raw-edge, top stitched seam. This means first sewing the sleeve seams wrong sides together. The sleeve seams are curved – one generally a “convex” curve (the shirt bodice) and one generally a “concave” curve (the sleeve piece). The way you pin and sew these seams will make a difference in the ease of sewing. When pinning curves that have opposite lines (concave vs. convex), pin such that you’ll be sewing with the convex curve against the machine. To look at it another way, the curves will often look like they won’t match (don’t worry, if you cut accurately they will). Whichever seam looks like it has more fabric to be taken up during stitching, pin and place this piece against the machine. The natural action of the feed dogs will help subtly gather it (in the below photo, the brown is the sleeve, the natural-colorway the bodice. You can see the concave and convex curves):
When sewing – any time when sewing, but especially with a picky knit – hold the thread tails before you sew. This actually take a bit of practice. But if you don’t, your machine will often pull the thread tails into the machine’s throat plate. You’ll end up with a snarled-up bunch of thread and sometimes an ugly, bunchy seam. Observe the results when the thread tails were properly restrained:
After you sew each seam, you should steam press for best results. In general, it is always a good idea to “set the seam”, then press. “Setting the seam” is a technique I learned in a quilting class. It means pressing the seam just as sewn, before you turn it up and top stitch or whatever is next. Fabric is not two-dimensional but 3D – “setting the seam” helps integrate the seam into the structure of the garment (in this photo you can also see the nature of the zig zag that works well with stretchy knit sewing):
After you set the seam, go ahead and finger press it open and press with the iron again, this time in the formation you’ll want it in before proceeding. In this case, the seam allowances are pressed toward the bodice and then top stitched down for a deconstructed-look finish. Since the seams are curved, it makes sense to use a tailor’s ham (although this is rather optional):
The final touch in the raglan bodice/sleeve seams is the top stitching with the raw edge finish. I chose to do this from the inside of the shirt. This is because the stabilized portion of the pattern pieces would be travelling across the feed dogs. When I tried this from the outside of the shirt (as you typically do with top stitching) the seam process distorted the fabric and made a wonky seam, so I flipped the shirt. As long as you go slowly and make sure to gently pull the seam open, sewing from the backside of the garment lends a good result:
Since I made the “puff sleeve” version of the garment, the next steps in the pattern were to gather the raw edges of the sleeve hem into the two strips that will form the finished sleeve. This is done by a long basting stitch on the sleeve’s raw edge to gather the sleeve, then applying the two edge strips simultaneously. Again, the importance of securing the thread tails before you sew will result in a clean finish:
After attaching the sleeve strips, you press them together (hiding the raw edges of the sleeve end) and top stitch. Easy-peasy!
For a more subtle finish, you could use a matching thread instead of the contrast I have done here.
The side seam is one of the last remaining aspects to shirt construction. I elected to do a typical finish – that is stitch it right-sides together, then finish the inside seam allowances for sturdiness. One nice thing with a knit is you usually only have to pin at the top and bottom of a seam. Go slowly and stretch to fit and you’ll have lovely results. I sewed at a 1/2″ seam allowance (instead of the pattern’s 1/4″), because I knew my skinny-minnie daughter would fit just fine, and I wanted to trim the seam down to a clean edge before finishing the seams:
After trimming, and then stitching along the seam allowances:
The neckline is probably the trickiest part of this particular pattern, but it is an ingenious little treatment that not only looks fabulous but is a lot less trouble than most self-finished necklines. Two strips are sewn, one at a time, first to the outside of the garment than the inside. Both strips are simply overlapped at each short end. The outside strip is sewn at a slightly wider seam allowance. Thus when you press up both strips the seam line will cover itself. The only thing that remains is to sew a tiny rectangle, anchoring the overlapped ends of the neckband at the back-left shoulder.
So first, pinning:
I always imagine the Beginner stitcher is alarmed at this point. The neckband of shirts is always so much smaller than the shirt opening! But, that’s the point. This strip, cut against the knit grain, will pull the shirt neckline in to lie flat on the body. Again, you sew with the strip facing up and the shirt neckline against the machine. Carefully pin at a few places and stretch and the whole thing comes together like a dream.
Although the pattern doesn't have this extra step, after attaching each neckline strip I prefer to trim the seam at 3/16″ from the innermost seam, then press up and top stitch:
Here’s the best trick I know regarding top stitching: go slow! Very few of us make “perfect” top stitching but the slower you go, and the more you practice, the better things will look.
Finally, stitch the little rectangle at the back-left shoulder seam where the strips overlapped. The best thing about this little square is it will look different every time. It’s like a signature:
Finally, either wash by hand or throw in the washing machine and dryer to rid the fabric of the crunchy stabilizer. Then present your client with their new shirt! After the cutting and stabilizing aspects of construction (which I typically do the night before and take about a half hour), the shirt takes less time to sew than it took me to write out this tutorial. It’s a quick and lovely creation.
Thanks again Kelly!
Have a wonderful weekend and Happy Sewing!
ps. visit again on Monday for a little Liberty giveaway. ;)