August 19, 2019

11 Easy Tips for Sewing Knit Fabrics Like a Pro

Sewing with knit fabrics can be extremely frustrating. However, with the right technique, you will become a pro in no time. Here are 11 easy sewing tips to get great results!

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Sewing with Knit Fabrics

Generally, knits are not my favorite things to sew. I find the fine quality difficult to work with because most knits have so much stretch. They catch in the machine, they are hard to cut and slippery to sew. I’ve been experimenting with some new techniques for getting professional-looking results. I’ve had to let go of my traditional sewing methods when sewing with knit fabrics and embrace some new ideas that make the entire process so much easier. I recently made this beautiful top using Simplicity pattern #S8391. Read on for my pattern hacks and adjustments!

I’ve come up with 11 easy sewing tips for knit fabrics. Perhaps you already knew these tips, but perhaps they will be new to you. Either way, knit fabrics are everywhere. Most people find them very comfortable to wear and prefer them over woven fabrics. I am probably in the minority of the folks that prefer wovens over knit garments for the best overall durability and coverage. But sometimes you have to step out of your box and try some new things. So here goes!

The front of this particular top has two layers of knits. One with the sheer web design, and the other a solid piece.

11 Tips for Sewing Knits

1. Pre-wash and dry your fabric before you start sewing. Knits tend to shrink a considerable amount, 20 percent or more in some cases depending on the fiber content. I prefer poly-cotton knits because they shrink less than rayon knits. I always wash and dry my fabric as I would the completed garment. However, I do wash my handmade clothes on gentle and dry on low or even line dry them. This particular novelty knit has big spider web-like holes in it that catch on jewelry, etc. so use extra caution when washing this type of fabric.

2. Make sure the fabric is on grain when you lay it out to cut. Knit fabrics can be off-grain very easily. It’s very important that you take the time to match your selvedges and edges as well as smooth out any wrinkles before you cut. If the selvedges don’t line up properly, stretch the fabric the opposite direction to straighten it until it’s even. Then press and steam it in place before cutting. This is critical to getting your pattern on grain when you cut it out. If the fabric is off-grain when cut, your knit project will never hang straight when you wear it.

3. Use a longer zig-zag stitch length to sew. Fine knits require a longer stitch length to keep them from being caught down in the feed dog of the sewing machine. I used a 3.0 or 3.5 zig-zag stitch to put the pieces together, then serged the seam allowances. Serging is optional as the knit fabric will not unravel in most cases.

4. Try using stabilizer under the seam for a professional finish. You can also use strips of either stick-on embroidery stabilizer or fusible interfacing scraps to help give more structure to the fabric as you sew. The tear-away stabilizer can be removed afterward as it is rather bulky. However, I have had considerable success with lightweight fusible interfacing strips too. The interfacing can be left in the seam, it will not show on the right side of the garment and helps to keep the seam from stretching as you wear the garment. This is particularly helpful with shoulder seams, as they can easily stretch out and not recover. Simply cut the stabilizer the same length as the shoulder seam and insert it as you sew.

5. Consider leaving raw edges at necklines, hems, and sleeves. This is perhaps the most difficult concept, but it makes things so simple! Knits do not unravel, therefore you do not have to finish every single edge all of the time. This concept is hard for me, as I tend to finish things all of the time. But, with this type of knit, it is so much easier and still looks great! Raw knit fabrics are in. You can see ready-to-wear garments in the stores that have raw edges everywhere. More on this technique below!

6. Pair two lightweight knits together for more body. This knit fabric was quite sheer. At my age I do not feel comfortable with sheer fabrics, I prefer more coverage. By layering the sheer fabric with the solid one behind it on the front of the shirt, it gives me the coverage I prefer. If I make this pattern again, I will also layer them in the back as I like the layered look so much better. The t-shirt front pieces were basted together before sewing to the rest of the garment.

7. Eliminate bulky facings. If you have been around the blog for a while you will notice I dislike facings. I was attracted to this particular pattern because it used strips of bias to finish both the neckline and sleeve. This technique is so easy to sew and doesn’t add any extra bulk to the lightweight fabric. The result is a shirt that looks just like ready-to-wear, as most ready-to-wear shirts have very few facings.

8. Use bias strips to clean finish hems. The sleeve hem gets the same treatment as the neck in this design. Easy to do, and gives the sleeve more durability.

9. Use open sleeve construction. This method of sewing the shoulders together, then the sleeve cap, and finally finishing the underarm sleeve seam all the way down to the hem is the technique used in ready-to-wear. Knit fabrics stretch so easily that sleeve caps end up with a smooth shape using this flat construction technique instead of sewing them in the round. Video coming soon!

10. Reinforce and tack the seam stress points. T-shirts have so much stress at certain points, this can cause holes in your shirt as you wear it. You can tack your seams with a bar tack, zig-zag stitch or simply use a few regular straight stitches back and forth. Places to reinforce are the seam at the bottom of the underarm, seams just above side vents, top corners of pockets, or bulky areas where fabrics join together at the back or side neck. I prefer to serge my seams, then tack the tails in place if they are not covered by more lines of stitching to keep them from unraveling.

11. Use 3 or 4 thread serged seams. I sew most of my knits with a 3 thread stitch. It gives adequate coverage and stretch, but you can use 4 threads seams for even more reinforcement. Keep in mind this is the icing on the cake, that is it is not structurally necessary to use either one but it will give you the most professional results.

Next time I will make the back the same as the front with two layers of knit fabric.

Pattern Hacks and Adjustments

1. For this Simplicity pattern, I lengthened the sleeves about 4″. The original design had a short cap sleeve, which would hit me in at the widest part of my arm. By lengthening the sleeve, the shirt now detracts from my wide biceps.

2. The front was cut from the novelty knit as well as the sleeve. Pieces were basted together, then assembled with the back and sleeve.

3. I added a gold button at the back neck for interest.

4. Neckline band and sleeve band were done with the bias binding method below.

Bias Binding Finishing Hack

1. Cut strips of bias 2″ wide.

2. Sew to opening with 5/8″ seam allowance.

3. Trim close to the seam.

4. Turn to the right side, press.

5. Stitch in the ditch to secure.

Notice I have not mentioned using a cover stitch. Cover stitching is a method of finishing both the raw edges and topstitching at the same time. Many of the newer serger machines have this option. It’s great if you have it available, but for those that don’t these techniques will still give you great results. I hope you will give them a try. I would love to see what you create over on our Chambray Blues Facebook group!