For Halloween, I needed to sew a lemon yellow sweatshirt for my husband to complete his Michael Jackson werewolf costume (if you don't know what I'm talking about, I invite you to rewatch the Thriller video 😊). So, I thought it would be a great article to show you how to assemble a sweatshirt entirely with a serger and share my tips and tricks. 

So, let's get started! 

The pattern: What should you watch out for?

1. To make a sweatshirt, you will need a sweatshirt pattern; you might say "well yes, that's obvious," but it's important to note because the pattern will be adapted to the fabric's elasticity. Designers take knit elasticity into account to create patterns that fit. Often, these patterns are "smaller" than patterns for woven fabrics. 

2. Refer to the size chart to choose your size. After measuring yourself, check the reference chart provided with the pattern. Indeed, just because you wear a commercial size 40 doesn't necessarily mean it corresponds to a size 40 in your pattern. Pattern sizes can vary; there are no standard references; that's why you sometimes hear "Burda runs large,...".

3. Watch out for seam allowances! Check your pattern to see if seam allowances are included or not. Note that if you use a serger and trim your seam allowance slightly, it's good to have a seam allowance of 0.7 - 0.8cm. If it's 1cm, you'll need to trim more or adjust the knife on your serger. 

There are many brands and styles of sweatshirt patterns; be sure to carefully read the brand-specific recommendations. In the shop, you will find women's sweatshirts from the brand IAM patterns that are very well explained.

For my husband's sweatshirt, I chose the NAND model from Maison Victor May/June 2017 issue, which I really modified a lot: I removed the front pocket, took out the sleeve seams, and worked with two sizes to match his actual measurements. 

Cutting the fabric and ribbing: What should you watch out for?

1. Properly place your pattern pieces along the grainline and be careful to position the front and back on the fabric fold. 

2. Clearly mark the notches by slightly snipping the knit (2-3mm is enough), as these notches are very useful during assembly steps

3. You can use ribbing in band or tubular form for the cuffs and hem. In the case of tubular ribbing, don't hesitate to cut the side of the ribbing to lay it flat and more easily cut the neckline and hem bands. 

You will find tubular or band ribbing in the shop. For the sweatshirt shown, I used white tubular ribbing. 

Assembly preparation: what should you pay attention to?

To assemble your pieces before sewing them, there are three possible techniques that I will detail. The choice of technique will depend on your preference but also on your desired level of attention and precision.

Why the level of attention? Because to assemble your sweatshirt on the serger, you will use the serger knife to neatly trim the raw edges. And this very knife hates needles... If a needle hits the knife, it's ruined! Most of the time, the piece will have to be replaced. So if you use needles, you need to be very focused and attentive.

Why the level of precision? Because depending on the chosen method, your seam matching will be perfect or sometimes a bit approximate... so it depends on your level of demand. 

The three methods to prepare the seam

1. The wonder clips - the plastic clips

This works very well for materials with quite a bit of thickness and since you can't miss them, there are very few "accidents" of clips passing into the knife. You can see them clearly and remove them as you go, which is a definite advantage. However, the precision level of these clips is much lower than with the other two methods. 

2. classic pins

For seam preparation, you can also use pins by inserting them parallel to the seam. This prevents them from going into the knife. It takes a bit of experience to place them correctly. I recommend offsetting them slightly to avoid the serger foot passing over them and irreversibly marking the fabric (due to the foot's pressure on the pin). This method requires attention but allows for more precise matching. 

3. basting thread

This method is the Rolls-Royce, especially if you have very slippery fabrics or a lot of ease to absorb. It has the advantage of not causing any problems with the serger knife. The downside is obviously the time, especially if you are not used to making basting stitches. 

You will find in the shop the materials to carry out these three methods. My favorites remain the needles and the basting thread. 

Let's move on to the serger: how to prepare?

1. Check your threading carefully with two jersey needles matching the needs of your serger (see your brand's manual)

2. Place the 4 cones or spools of thread corresponding to your project

3. Make sure the knife is active

4. Before starting to sew your project, do tests with scraps to adjust the tension discs. 

There you go, you are ready to sew!

Here are the assembly steps

1. Sew the shoulders and the front and back sides right sides together

2. Close the sleeve sides (to form a tube)

3. Sew the sleeves to the body, carefully using the notches and easing the sleeve cap. This will allow you to make great matches 😊

4. Close the neckline band and stitch right sides together. Do the same with each cuff. 

5. Sew the sides right sides together of the ribbing bands at the bottom of the body

6. Fold all the ribbing pieces in half lengthwise (wrong sides together)

7. Slide the ribbing cuffs around the sleeves, pin the raw edges all around

8. Sew the cuffs

9. Place the neckline band, making sure to place the ribbing seam at the center back. Then, pin all around according to the notches right side of the ribbing against the wrong side of the body. Sew together

10. Repeat the same operation with the bottom of the body, but this time aligning the seams of the ribbing with the side seams. 

Ta-da! It's almost finished and yes because the step of tucking in the threads remains.

There are two methods for this:

- or you tuck the threads inside your overlock with a needle

- either you untangle the overlock threads up to your fabric. You have two longer threads that correspond to the looper threads of your serger. You give a sharp pull and a knot will form. You just have to cut. 

And there you go, this time it's really finished and all that's left is to put on your sweatshirt!