Thursday Tip with Hali - Sewing with Knits
Thursday Tip // Sewing with knits
Knit fabrics have a reputation for being challenging to sew but we say, you can do it! We hope today’s blog post will give you some tips for success when sewing with knits or the confidence to give it a try if you haven’t ventured there yet. And if you want some in person help, The T-shirt Class is a great place to start.
Choosing a size
Choosing the right size based on your body measurements can be tricky at the best of times. Especially if you are fairly new to sewing. When choosing a size for knit garments, there are several things to consider. All garments have a measure of ease built into the pattern. This is usually based on the type of garment and the intended look of the garment. If the garment is meant to fit tight to the body (eg. undergarments, base layers, swimwear) the pattern will have negative ease.
Negative ease means the finished garment measurements will be smaller than your actual body but because of the stretch in the fabric it will still fit your body comfortably with room to move. Conversely, positive ease is when the finished garment measurements are larger than your body so the garment itself is looser fitting or can be made in a woven fabric with zero stretch because the amount of ease allows you to still put the garment on and move in it.
Ease is important to consider when choosing a knit fabric for your pattern. Make sure to check the pattern instructions for the fabric stretch percentage needed for the garment (if you aren’t familiar with stretch percentage, check out last week’s tip here). If you choose a fabric with a greater stretch percentage than what the pattern calls for, you may end up with a much larger fitting garment than intended. Or vice versa, if you choose a fabric with less stretch than needed, you may not even be able to put the garment on.
If you are making a pattern with neckbands, cuffs, waistbands etc. also consider the stretch percentage. For example, our 100% Organic Cotton Jersey has stretch in both directions, however, due to it being 100% cotton it doesn’t have the recovery needed for most pattern drafted bands, such as a neckband or wristband. You’ll likely need to add a bit of length to the band piece in order to get it to fit properly.
Preparing to cut and sew
We always recommend pre-washing your fabric. You can wash in the way you intend to wash your finished garment, however we often say wash cold and lay flat to dry. Knit fabrics with a lot of drape or heavier weight knits can stretch out if hung on a hanger or drying rack.
Depending on the fabric content, knit fabrics can be a little slippery or shifty while cutting. Knit fabrics with a lot of drape or softness (eg. our Lyocell Organic Cotton Jersey) tend to slip off the table or shift around on the floor quite easily. We recommend taking some extra time to make sure your pattern pieces are lined up properly to your grainline; you could even cut on a single layer to be extra sure. If you cut on a table, make sure your fabric isn’t draped over the side as it can stretch out and distort your pattern pieces that you cut resulting in pieces that don’t fit together or notches not lining up.
Keep in mind the direction of greatest stretch (DOGS) as well. You can read more about that here, but basically you want to line up your pattern pieces so the direction of greatest stretch will wrap around your body. This may mean you need to cut pieces out on the crossgrain.
We highly recommend using pattern weights with a rotary cutter and mat for cutting out knits. Pins can be a little trickier with slinky fabrics so if you use pins and scissors just be careful to pin perpendicular to your pattern piece so the fabric doesn’t bunch up underneath your pattern piece causing the piece to distort in shape.
Choosing the right needle
For most knit fabrics you will want to use a ballpoint or jersey needle. These needles have a rounded tip so they slide easily between the fibres instead of piercing or breaking the knitted fibres. For knits with spandex content you will typically use a stretch needle.
It is also important to consider the weight of your fabric when choosing a needle for your project. For lighter knit fabrics like our Ecovero™ Jersey, Cotton Spandex Jersey or Ribbed Tencel Modal use a 75/11 stretch needle. Whereas, heavier fabrics like our Recycled Fleece (40% Recycled Polyester, 40% Recycled Cotton, 20% Recycled Wool) would be better suited to a size 90/14 ballpoint needle because it doesn’t have any spandex in it.
Staystitching: If the pattern says do it, then do it! Knit fabrics can stretch out in the same way woven fabrics can. Under the weight of the pieces and moving them around your sewing room they can easily grow and stretch causing them to change shape and no longer line up as intended. Ask me about my track jacket zipper fiasco sometime. Trust me, not worth skipping this step if it’s recommended in the pattern. Read here for more info on staystitching.
Sewing with knits
When sewing with knits, take your time and try not to stretch the fabric as you sew. A walking foot attachment can be very helpful to help the layers of fabric feed evenly under the foot. When sewing neckbands or cuffs don’t be afraid to baste the band together with a zigzag stitch first so the layers don’t shift while sewing to the neckline or sleeve. Fortunately with knits it is not necessary to finish the raw edges because they won’t fray.
To achieve a better result, especially for necklines, remember to FEED THE EASE. When you are ready to sew your seam make sure the longer length of fabric is touching the feed dogs. In the case of a neckline, you want the body piece of the neckline touching the feed dogs and the neckband piece on top, directly under the presser foot.
For hemming, you can use a traditional zigzag or other decorative stretch stitch if your machine has them. A twin needle is also a good option for hemming to get that ready-to-wear look with a double line of parallel stitches.
Can I press knit fabrics?
YES! Yes you most definitely can, and you should! Generally you will want to use a low heat setting on your iron but follow the fabric listing recommendations if available. If you have a bit of a wobbly seam then a good press can often sort that out and make it look smooth and delightful.
Our next T-shirt Class starts Nov. 4!