Sewing seams on knit fabrics
S
critters.
If you don’t like the idea of painting a stabilizer on
your fabric, you can also use a fusible (all-bias)
knit stabilizer. Purchase this on a bolt and cut into
1/2” strips, or buy on a spool. This is an iron-on
product that’s also great for hems - we’ll discuss
hems in another section!
I recommend getting to know your machine well.
Learn how to change your presser foot pressure
(if you have that), adjust the tension, and how to
change stitch length and width. Also look through
your manual to find out any programmed stitches
that are recommended for knits. Most machines
in the past 15-20 years have a variety of different
options for you to use. Below are a few of
suggestions, but practice and trial-and-error (on
scraps!!) are your friends.
Options for Sewing Machines
©Birdsong™ and Deanna D. McCool 2013
ewing with knits can seem intimidating, but
it doesn’t have to be, with a few new ways
of doing things. Knits aren’t necessarily more
difficult to work with, but they are different! Mostly,
you’ll need to ensure that your seams remain
stretchy. Be sure to use a stretch needle!
Working with curly edges
F
irst, you don’t need a fancy machine. Simply
having a machine that does a zigzag stitch will
ensure a stretchy, but sturdy seam!
Option 1: Zigzag with stretched straight stitch
• Lower your tension just a bit (if it’s on a 5,
move it down to a 4). If you have the option,
decrease your presser foot pressure. You’ll
likely have to decrease it more for a thinner
knit than for a thicker knit. If you don’t have
this option, add tissue paper to your seam on
top of your fabric and under your presser foot.
It will prevent additional stretching and can be
pulled off the seam when you’re done.
Edges of some knits are especially curly. If you
don’t want to deal with this (either on your regular
sewing machine or your serger), you can “paint
on” a washable stabilizer - dab, don’t sweep
and stretch - or make your own with 1/2 Tbsp
of cornstarch mixed with 1 cup of water. Once
painted on, the stabilizer must dry before you
sew. You can either let it sit - or for impatient
sewists like me - use a hairdryer to dry it. If you
use the homemade stabilizer, be sure to clean
up afterwards because cornstarch can attract
• Use a medium zigzag stitch, and sew along
the edge of the fabric without stretching. Start
about 1/2” down from the top, because knits
are notorious for dragging down into the throat
plate when you start. You can always turn
the fabric over and sew the other direction
when you’re done. Alternatively, you can run
a piece of scrap fabric through the machine
first, then put the knit under the presser foot
immediately afterward. Don’t stretch while
you sew. Remember to backstitch at the
beginning and end!
• At the seam allowance (1/4” - 1/2”, depending
on the pattern), sew a regular straight
stitch, with a medium-to-long stitch length.
Backstitch at the top and bottom and stretch
while you sew. Make sure you stretch - not
too hard, or your fabric will be wavy - but a
medium stretch for the type of fabric you’re
using.
• For what we’ll call “heavy traffic areas” underarm seams, crotch seams - sew over
this seam allowance one more time with a
regular straight stitch, stretching gently.
Option 3: Sewing machine with walking foot
Purchase a walking foot for your machine. Some
machine models have very pricey walking feet but others don’t, and you can often get a
“generic” walking foot to go with your machine
to save money. What does a walking foot do?
Normally a sewing machine works by feeding
the fabric using the feed dog only. When this
happens with knits, the fabric’s stretch causes
the top and bottom to feed unevenly (much
more so than on a woven). A walking foot has an
additional top piece that feeds the top layer at the
same rate as the bottom layer.
Option 2: A regular ol’ zigzag
• Just as above - decrease the pressure foot
pressure or add tissue paper on top of your
fabric, under the presser foot (photo in next
column shows the tissue-paper method).
• Set your sewing machine to a zigzag at a
slightly-lower-than usual stitch length (around
a 1.5-2) and a width of 3-3.5.
• Don’t stretch while sewing - just sew at
the seam allowance, backstitching at the
beginning and end (remembering to start 1/2”
down and returning to the beginning, to keep
the fabric from dragging into the throat plate).
You can sew using the same methods described
in the section above, or you may find a stretch
stitch on your machine that’s suitable. Some
machines have a “triple stretch stitch” that looks
almost like a straight stitch when completed, but
actually is a series of stitches that allow the fabric
to stretch...and then you won’t have to stretch
while you sew!
Also, with a walking foot, you likely won’t have
to worry as much about presser foot pressure or
use the tissue-paper method, but experiment on
scraps first.
Additional Tips
class, Beginner Serging: http://www.craftsy.com/
class/beginner-serging-machine-basics-andtechniques/123 . If nothing else, it will force you
to spend some good quality time with your serger
so it becomes your friend, and not your foe!
Want a really stretchy seam?
Try Maxi Lock thread in the bobbin! It’s stretchy
but not exactly an “elastic” thread, so you can
wind your bobbin the same way you’d wind any
other bobbin - no need to hand-wind.
Also note - with these methods, it’s unlikely
you’ll have a wavy, stretched-out seam. BUT sometimes there’s still waviness around collars
and other places (we’ll talk about collars and
hems in another section). This can be OK.
Pressing will often take out most of this waviness.
And something that might look slightly wavy on
the table will likely look perfect on the body!
Is a bird nesting here?
It’s a common problem to get a “thread nest”
on the back of your work. Not pretty! But you
can avoid this by holding onto both threads (top
and bobbin) at the beginning of your seam, just
for the first 2-3 stitches. Do this every time you
start sewing - even on wovens - and it’s “Bye,
Bye, Birdie Nest.” Soon this will become secondnature.
Sewing Knits with a serger
I
t took me awhile to decide to purchase a serger,
but now that I’ve been using it for quite awhile,
I’m considering an upgrade! Sergers are great
for knits because they allow the seam to remain
stretchy. First - just as with the sewing machine
section - get to know your serger! Although I
might publicly profess to love my serger, it can
be a love/hate relationship because it has to
be threaded perfectly and settings need to be
accurate or it simply doesn’t work right. These
machines can act like divas. If you’re fairly new
to serging, I highly recommend this Craftsy
Here are few tips for sewing knits with a serger:
• You do NOT need to stretch your fabric while
stitching on a serger.
• You can stitch with either 3 or 4 threads; I
tend to use 4, but it’s personal preference for
a slightly more secure seam.
• On those heavy traffic areas we talked about
before - crotch and rear seams, underarms - I
will zigzag within the seam allowance on my
regular machine first, then go over it with my
serger, making sure I don’t cut off the zigzags.
This gives some extra protection.
• Use a closer-than-average stitch length on
lighter-weight knits and a longer stitch length
on heavier knits.
• If your seam is a bit wavy, and if you have
differential feed, raise the setting a bit. That
should take care of it! Otherwise, just make
sure your tensions are balanced.
Now, practice with some knits, and decide which
methods - or combination of methods - works
best for you and your machine!
To see the first tutorial, Getting Started With
Knits, visit: http://www.birdsongbows.blogspot.
com/2013/03/free-tutorial-how-to-sew-with-knits.
html