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Altering the Armscye & Sewing with Knits

image of black and white cotton fabric on top of a wool throw and accented by yellow flowers
Both fabrics for the top are GOTS interlock cotton, but the black is mercerized. I ordered from Lebenskleidung from Germany.

I’m still fairly new to sewing and have an expectation that patterns will be sized to fit actual people and not the stick figures that fast fashion has deemed the standard. However, I’ve found I encounter the same issues with sewing patterns as I do with store-bought clothes: the arms are made far too small. I can either go up a size and have a giant shirt that fits my arms or deal with the constriction around my biceps.

This is where the magic of sewing and alterations come in! I have found sewing alone isn’t enough, because I’ll still end up having to choose between an ill-fitted shirt or hulking out on my arms. I made a dress as my first sewing project and I was so excited to try it on, only to discover I literally couldn’t fit the sleeves over my biceps. 🙁

Now that I’ve decided to sew my entire wardrobe, I’m revisiting this issue, tackling it head-on, and sharing what I’ve discovered with you! The shirt I’m sewing is called the Ensis Tee from Papercut Patterns. Unfortunately, it was discontinued shortly after purchasing, so I’m just going to cover how I altered my bicep and armscye and not what I thought of the pattern. Here’s a resource with all the unfamiliar sewing words to get you through this post!

This was also my first time sewing with knits, so I’m going to cover what stitches, needles, and tricks I used to sew my shirt on a basic sewing machine!

Decide if you need to alter the arm OR the arm + armscye

First thing’s first, you need to take accurate measurements of your arm and armscye to figure this out. Don’t be like me and omit the armscye until the last minute and realize that needs to be altered too. 🙂 I had a difficult time figuring out where I should be measuring my arm, but thankfully I came across an article from Threads Magazine that covers it thoroughly, and it is free! The circumference measurements that are important include: armscye, bicep, elbow, and wrist. You should also measure the length of your arm from shoulder cap to elbow to wrist.

Now draw the seams for your pattern along the entire arm piece and the front and back pieces that have the armscye. Mark your elbow on the pattern as well. You now have all the tools to evaluate what alterations are needed. Take the widest section of the arm and measure the width, compare this to your bicep measurement. Do the same for your elbow and wrist. Last, stand your ruler on its edge and trace the armscye around the front and back top pieces along the seamline. Remember to include ease in your measurements! I think up to 3/4″ for knits and 2″ for woven is recommended.

picture of a sleeve for a sewing pattern marked horizontally and vertically, ready to be altered.

For me, I needed to add width to my bicep and the armscye. If this is the case for you, skip to the next section. If you only need to add width to the bicep area, continue reading as I’ll go over the process for lifting the sleeve.

Lifting the sleeve

This is rather simple, once you see how to do it! I found a great article that goes over lifting the sleeve in-depth, if you want more information. You will need to mark two lines, one that goes vertically along the center of the arm piece and another horizontally. The horizontal line should be marked at the widest area of the pattern piece (where you compared your bicep measurement to) using the seam lines.

I didn’t do this part as I needed to alter both the arm and armscye, but you will need to cut through the pattern piece, starting from the inside to the edge. Leave a little bit of a hinge on all four edges. Now you can simply pivot your arm piece to add the width you need! I thought this was a really slick way of altering the arm, because it doesn’t change the armscye at all. I do think this would shorten the arm length, so you should double check that when you’re done adding width.

Alter the Arm + Armscye

I went about altering the arm piece first, then adjusted the armscye to fit the new sleeve cap width. If the armscye is your bigger problem you might want to do the reverse. I had contemplated just grading between two sizes to get the arm to work, but I didn’t want to change where the sleeve cap sat on my shoulder or make the armscye really large.

I started by marking the arm piece down the center, parallel to the grainline. I had already marked my elbow location, which I used as a stopping point for adding width. My elbow to wrist area didn’t need any extra material, but you could easily split the arm piece all the way down to the wrist, leaving a hinge.

The arm fits comfortably with the alterations! I wouldn’t want it any smaller, so I’m glad I added the 1/2″ to the bicep and lowered the armscye.

I next cut the arm and added 1/2″ to the widest part of the sleeve. This translated to 3/4″ at the top of the sleeve cap. I also cut at the elbow line towards the center, but left a hinge, to allow the pattern to lay flat.

Translating the extra 3/4″ to the armscye worked out well for me, but if you’re adding more than 1″ to the sleeve, the math may not work out as well. I divided 3/4″ by 2 and lowered the armscye by 3/8″ on the front and back armscye pieces. I graded the lowered armscye to about the center of each piece.

To check that the math works out (the sleeve cap circumference and armscye are the same length or are the same difference that the pattern pieces originally started out as) walk a flexible ruler along the SEAM LINES of the sleeve cap and compare that to the front and back armscyes added up.

If you need to add a lot of width to the armscye, I might just uniformly offset the armscye instead of grading to the center, but I haven’t needed to test this myself.

On to the next step… learning how to sew with knit fabric!

Knit Fabric Sewing Tips

image showing the details of a handmade shirt to show you can sew knit fabrics with a standard sewing machine

As a new sewist, I would love if patterns that are deemed “easy” would have a disclaimer if you needed special equipment. I didn’t have any special sewing needles or pins to ensure no snags, so I purchased jersey and stretch needles and fabric clips. I ended up using the jersey needles and didn’t have any problems. The clips were great, although a little heavy since I was being careful not to stretch my fabric while sewing.

I didn’t realize that special sewing machines are used for sewing knits. Thankfully, there’s quite a few tricks to sew with knit fabrics using a standard sewing machine. I found a really insightful blog post by Seamwork, that goes through the different stitches you can use when sewing knit fabrics. I chose the triple straight stitch because my fabric is an interlock and knew I’d be pressing the seams. It worked really well and provided ample stretch, even around the neck, which needed to stretch to fit over my head.

The one area I didn’t use the triple straight stitch was the hem. I referenced a different blog post, since I had never even heard of a coverstitch machine and why I’d need one for hemming knits. Thankfully, a twin needle did the trick for topstitching. I did have some issues, but hey, the hem is at least done and looks good.

close-up image of the finished sewn top, showing the stitching made using a twin needle
You can see some tunneling between the two lines of stitches. This can be fixed by changing the bobbin tension, which I didn’t bother doing.

Based on my machine eating my fabric while using the twin needle, I would recommend using tissue paper underneath your sewing. It will be easily torn off once you’re all done and ensure you don’t have to last minute raise your hem to remove a hole in your fabric. I would also recommend testing the twin needle out to make sure the tension is correct. I don’t think I can change the bobbin tension on my basic Brother machine, but I also didn’t look too hard as the stitching looked decent. Next time, I’d take a look further to ensure perfect stitching.

Hopefully this write-up has helped you on your sewing journey! If you’d like to see an overview of the project, watch my YouTube video below.

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