A seam is a line of stitching that joins two pieces of material. Sounds simple, right? But there are many different types of seams, and each has its own procedure, appearance, and usage. You can sew a seam by hand or by machine. Either way, it’s not hard if you have the tools and know the techniques.
Different Types of Seams
So you need to join your pattern pieces. Of course you want to do it in a way that’s both effective and attractive. That means it’s time to choose the type of seam that you’re going to use.
Decorative Seams
Decorative seams, as you probably guessed, are there to enhance the appearance of your project. This type of seam may join pattern pieces, but in addition, they may:
- Add shape to a garment
- Enhance the structure of part of a garment or other item
- Add color, texture, or other visual interest
Decorative seams are made to be seen, so technique and attention to detail are important. Some types of decorative seams include:
- Princess seam
- Channel seam
- Linen seam
- Pleated seam
- Abutted seam
Want to seam what we’re talking about? Here’s a princess seam before, during, and after construction.
Functional Seams
Functional seams hold your item together. They’re meant to bear weight, stress, and strain. They should be strong, but they can also be decorative. Some examples of functional seams include:
- Straight seam
- Lapped seam
- French seam
- Flat felled seam
Here’s how to sew an attractive and functional French seam.
Single Seams
A single seam is a single row of stitching that joins two pieces of material. The seam edges may or may not be finished, but they will always end up on the inside (or reverse side) of your item. Depending on your fabric, you may want to finish your seam edges by pinking or serging them off, or by using a finishing technique like the Hong Kong finish, shown in the video below.
Double Seams
You’ll know double seams by their two parallel rows of stitching. The double rows make the seam very strong. They can also add a decorative touch. You can use a double row to seal off seam edges, too. This can be especially helpful if your fabric is prone to fraying.
The flat felled seam, shown below, is a common double seam used in bluejeans.
Open Seams
Open seams leave the seam edges exposed. This is fine if the edges will end up on the inside (wrong side) of your project. It’s also acceptable if you’re working with a fray-resistant fabric.
On the other hand, if your fabric is subject to fraying, or if you simply want a tidier finish, you might want to use a closed seam.
Closed Seams
Closed seams enclose the seam edges within the seam. Some examples of closed seams include:
- French seam
- Lapped seam
- Flat felled seam
Have you chosen your seam? Great! It’s time to get sewing!
How to Sew a Seam by Hand
If you don’t have access to a sewing machine, or don’t have the time to learn how to use a sewing machine right now, don’t worry! You can sew a seam by hand.
What You’ll Need
- The appropriate needle for your fabric
- Your thread (remember to match synthetics with synthetic thread and natural fabrics with cotton thread)
- Scissors or snips
- Pins
- Tailor’s chalk or a fabric marker (optional)
- Ruler (optional)
- Beeswax (optional)
- Needle threader (optional)
- Pinking shears (optional)
- Iron (optional)
Step 1: Prepare Your Fabric
Mary Poppins once said, “well begun is half done.” When it comes to sewing, it’s absolutely true. By setting up your fabric and your tools, you’re setting yourself up for success.
First, if you’re working with fabric that’s prone to wrinkles, iron it to make sure it lays flat. This will ensure that your pattern pieces fit together the way they’re meant to.
Next, line up your fabric edges. Don’t be sloppy, or your finished product will be sloppy as well.
Pin your pieces together. This will keep them from slipping and sliding around while you sew.
Finally, mark your seam line with a washable fabric pen or tailor’s chalk. Use a ruler for extra precision. It’s a lot easier to sew along a line than to try to eyeball your seam while sewing.
If you take the time to be organized and precise, your project will have a greater chance of turning out the way you want it to.
Step 2: Prepare Your Needle and Thread
Step 2 is optional, but many people find it helpful.
First, start with the right needle. For fine fabrics, use a thin, sharp needle. This will minimize damage to the fabric. For thicker fabrics, you can use a thicker needle.
Snip your thread end at an angle. This will decrease the fuzz at the end, which can make it hard to thread the needle.
Dabbing beeswax onto your thread end can make the thread stiffer, which also makes it easier to poke it through the needle’s eye.
You can also use a needle threader. This is especially helpful if you’re working with a very small, very thin needle.
Now, thread your needle. You can choose to sew with a single thread, or, for a stronger stitch, pull the thread halfway through your needle, so that your needle is sitting halfway between your thread ends. Now, knot the thread ends together.
Step 3: Choose Your Stitch
There are a number of stitches you can choose from, but often the most straightforward stitches are the best. They’ll get you where you need to go quickly and with a minimum of fuss.
The straight stitch is the most basic sewing stitch. Some people also call this stitch a running stitch. It’s easy. Up and down in a straight line, from beginning to end. Here’s how it’s done.
A backstitch is another simple stitch. You might use this one if you want a stronger row of stitches.
Step 4: Sew Your Seam
Fabric prepared? Stitch chosen? Needle threaded? Now you’re ready to sew!
Before you begin, secure your thread end. If you’ve already knotted the ends together, this will suffice. You can also use one of these techniques.
Now, using your chosen stitch, sew along the line you marked earlier.
Step 5: Tie off Your Stitch
When you’ve completed your seam, it’s time to tie off your stitch. There are a number of ways to do this, including:
- Tying a knot
- Using a finishing stitch
- Making a French knot
- Using a backstitch
For a detailed photo tutorial of these and other methods, check out our article, How to Tie Off a Stitch.
Step 6: Finish Your Edges (Optional)
If you’re working with a fray-resistant fabric, or if you’ve chosen a seam that encloses the seam allowance, then you don’t have to finish your edges.
But if your fabric is likely to unravel, or if you simply want a tidy finish, then you might want to finish your edges.
If you’re sewing by hand, the easiest way to do this is to trim the seam allowance with pinking shears.
Advanced finishing techniques like a Hong Kong Finish are easier with a sewing machine. But if you have the time and patience, you can also adapt the technique to hand sewing.
Step 7: Iron Your Seam (Optional)
Ironing your seam on the right side of the fabric will help it to lie flat. This, in turn, will make your item look more professional and attractive.
How to Sew a Seam With a Sewing Machine
If you have a sewing machine, it’s easy to make a fast, strong, and precise seam.
What You’ll Need
- Your sewing machine
- The appropriate sewing machine needle for your fabric
- Suitable thread for your fabric
- Scissors
- Pins
- Beeswax (optional)
- Pinking shears (optional)
- Fabric stabilizer (optional)
- Sewing machine needle threader (optional)
- Iron (optional)
Step 1: Prepare Your Fabric
Preparing your fabric for machine sewing is similar to preparing it for hand sewing. You’ll need to:
- Iron the fabric, unless it’s wrinkle-resistant
- Line up your fabric edges
- Pin your seam together
You might want to mark your seam line at this point. You could also use the guide on your sewing machine’s feed cover plate to eyeball your seam line.
Also, if your fabric is slippery, lightweight, or doesn’t hold its shape well, you might want to stabilize it. If your fabric is machine washable, you can use a wash-out spray stabilizer. If it’s not, you can stabilize your fabric by pinning tissue paper, tracing paper, or a commercial tear-away stabilizer to the back.
Step 2: Prepare Your Needle and Thread
Always use a new needle for every project.
In addition, there are a bewildering number of needles on the market. It’s important to choose the right sewing machine needle for your fabric.
- Universal needles work well for many, but not all fabrics.
- For woven fabrics, use a ballpoint needle to minimize fabric damage.
- Use a stretch needle (jersey needle) for stretch fabrics.
- Thick materials like denim or leather need a sharp needle rated for that material.
- Lighter fabrics need a smaller, thinner, lighter needle.
- Match your needle size with your thread weight.
- Also match metallic thread with a metallic thread needle.
Regarding thread, match your thread to your fabric. Choose synthetic thread for working with synthetic fabrics, and cotton thread for natural fiber fabrics.
Also, polyester thread has a natural stretch, so use this, rather than cotton thread, if you’re working with a stretchy fabric.
Just like when threading a hand sewing needle, using beeswax on your thread end can make threading a sewing machine needle easier.
You can thread your needle using your sewing machine’s automatic needle threader. If your sewing machine doesn’t have one, however, you can use a sewing machine needle threader.
Step 3: Choose Your Stitch
A straight stitch is most people’s stitch of choice. However, if you’re working with stretchy fabrics, then choose one of your sewing machine’s stretch stitches.
If your sewing machine has an overlock or serging stitch, you can also use this to simultaneously sew your seam and finish your edges.
Here are some other types of stitches and their uses.
Step 4: Sew Your Seam
Line up your fabric with the appropriate markings on your feed cover plate. Alternately, if you’ve marked your seam line, line that up with your needle and sew your seam.
To secure your row, sew a locking stitch at the beginning of the row and at the end. Here’s how.
Step 5: Finish Your Edges (Optional)
As with hand sewing, you can finish your raw edges to keep them from fraying, or to give your item a more professionally finished work.
Here are a few different ways to finish your edges.
Step 6: Iron Your Seam (Optional)
Again, ironing your seam on the wrong side will help it to lay flat, and give your project a more finished look.
It’s Easier Than it “Seams”
It might look like a lot of steps for a straightforward task. But if you use the right tools and take the time to do it right, it’s easy to make a strong, attractive seam.
What’s your favorite seam? Do you have a technique that can make it easier for our readers? Tell us all about it in the comments!