Knits: 3 Tips for Easier Sewing by Nicole

March 5, 2014 by Nicole at Home 2 comment(s)

When the opportunity came up to work with some of the beautiful Britex knits AND use a pattern from one of the independent patternmakers newly affiliated with Britex, I jumped on it. Not only did I already have my eye on this dotted viscose/lycra blend fabric, but I had the perfect pattern in mind, too: the Renfrew cowl neck from Sewaholic.  I've made the top a few times, but love the fit and shape so much, that I was excited to sew it up again in this lovely, drapey fabric.


The Renfrew is a knit top designed with features to make it easier to be sewn on a regular sewing machine (such as cuffs for the sleeves and hem).  Of course, a serger can be used instead, but if you don't have one, you can still sew up this lovely top!  In today's post, I'll be talking about some of the basics of working with knits, for both regular machines and sergers/ coverstitch machines (for other tips on working with tissue knits, see Kristin’s post here).

First off, always wash and dry your fabric as you would care for the garment once it's sewn.  For this fabric, I washed it in the machine on cold and dried it on a normal setting. Knits shrink in both directions, and sometimes reveal their demons only once washed (curling edges, uneven selvages, etc.), so it's imperative to wash and dry before beginning.  Second, switch out your universal needle for a ball point or stretch needle.  These have rounded tips to slide through the fibers, preventing snags and pulls.


TIP ONE: Remember knits wiggle!

Knits are often manufactured in a long tube, which is usually sliced down one side to create a flat piece.  Therefore, you can't rely on selvages (as you can for wovens) to determine the untwisted grainline. Instead, pull gently cross-wise on your fabric to find the tiny ribbing (if your knit has them).  Fold your fabric with the ribbing running parallel to the edge of the fabric.  The image below shows the ribbing off-grain (as indicated by the arrow).


If you see rippling as you smooth over the folded edge, the grainline is not aligned properly (see below, for a dramatic version of what this looks like!)


Once the grain has been determined, carefully lay out the pattern and use weights (or objects around your sewing room!) to keep the pieces in place, then cut with a rotary cutter with a sharp blade.  Using pins and cutting with scissors can cause the fabric to shift around too much, distorting the fabric, and thus the garment pieces.




TIP TWO: Sewing seams with stretch!

The best part of wearing knits is also what makes them so difficult to sew: stretch.  Not only can the fabric be distorted under the presser foot, but when worn, sewn seams must stretch along with the fabric. To prevent distortion, use a walking foot or a dual feed foot, if your machine has that option.

To sew knits so that the seams stretch, there are a few options.

- On a regular machine, sew in a moderate zig-zag.  The greater the width of the zigzag, the more stretch it can accommodate, however, you don't want a very wide since the seams can begin to show from the right side.  With a zigzag stitch, the seam itself has depth, so they must be pressed to the side.


- While sewing your zigzag seams (or if you must use a straight stitch), use thread with stretch in the bobbin (such as Stretch Thread or Wooly Nylon). This adds additional stretch into you seams.

- And of course, you can use a serger.  A four-thread overlock is ideal for most cotton knits.


However, stretchy seams can be a problem in some locations, such as shoulder seams.  So for key weight-bearing locations on a garment (shoulder seams, waistbands, some neckbands), clear elastic can be used to provide extra strength.  For the shoulder seams, I used 1/4" clear elastic.


I usually baste these onto the wrong side of the shoulder seams before sewing the shoulder seam itself.   Be sure to use a walking foot or Teflon foot, since the elastic sticks to the plastic and metal parts of the sewing machine.


Keep in mind, various pattern companies have different seam allowances for knits, so be sure to look for the allowance in the instructions.  For the Renfrew, it is a 5/8" seam allowance; others will give 1/4" or 3/8". When serging, you may have to use the blade to trim the excess if 5/8" is the seam allowance. However, when using a regular machine there is no need to finish the seams, just trim the seams to a 1/4" width to reduce bulk.


TIP THREE: Finishing touches!

For the Renfrew, hemming cuffs or hems is not an issue, however, there are some really great options for creating a professional and stretchy hem on knit garments.

- For areas of a garment that don't need to stretch significantly (like the hem of a skirt), you can get away with a straight stitch (use the stretch thread in the bobbin to be safe!).

- Use a coverstitch machine or reconfigure your serger for coverstitching, if available.  This provides the most professional finish, with straight stitches appearing on the visible side and loops underneath to provide the stretch.


If you don't have a coverstitch machine, it totally doesn't matter!  A twin needle and some stretch thread will give an identical look, with a near-identical amount of stretch.  It's only a slight exaggeration to say that discovering twin needles changed my life :)


Twin needles come in various widths (distance between the attached needles) and are threaded simultaneously with two separate spools of thread.  Don't worry, you don't have to buy two spools--just wind a bobbin! Most machines have a place to add a separate spindle, but in a pinch, I've been known to put both spool and bobbin on the same spindle.


The effect is magical!  With a single pass, you get two perfectly parallel lines of stitches and the stitches have stretch since the thread underneath has to zigzag between the two upper lines of stitching.  Again, this works BEST with stretch thread in the bobbin, but regular thread can also work.  If you can, reduce the tension on the bobbin thread, which helps prevent the "tunneling" that can sometimes occur when the two straight stitches are pulled together by the zigzag underneath.


I used the narrow twin needle for securing the stitching on the cowl neckline:


After all that, here are some more photos of my finished Refrew top!


I worked to match up the stripes on the sides, but didn't want them to be completely continuous across the arms, so the stripes there are positioned slightly lower. For the sleeve and hem cuffs, the pattern is also uninterrupted.


This fabric truly works wonderfully for this pattern, especially for the cowl version.  It's slinky-drapey, but has enough body to be sewn with a regular machine.


Here's a view from the back.  The placement of the stripes on the cowl create a large dark swath, but the look from the front makes up for it!


I love this style because it can be dressed up or down, and is super comfy.  I'll probably wear this to work with khakis or a skirt (maybe even this one!)


Thank you to Britex for providing the fabric and thread, and Sewaholic for the pattern!  Please visit me over at Nicole at Home for more photos!

2 Response to Knits: 3 Tips for Easier Sewing by Nicole

  • susan d says:

    thank you - a real gift - long-awaited, wished-for well-fitted cowl jersey - very generous posting, thank you for sharing -- much to be appreciated.
    vty, s.d.

    December 31, 2014 at 2:02 pm

  • Britex Fabrics says:

    We equally appreciate Nicole's generous tips. Happy Sewing!

    January 5, 2015 at 1:31 pm