Sewing a straight seam is one of the first things beginner sewers need to do. Learn how to sew a seam either by machine or by hand with some scrap pieces of fabric before moving on to your sewing projects.
How to Sew a Seam | BY MACHINE
To sew a seam you will need:
- 2 scraps of fabric. I like using 5 x 5 inch (12 x 12cm) pieces as they are easy to handle.
- Your sewing machine
- All purpose sewing foot This is your regular straight stitching foot that comes with your machine. It is usually all metal or half metal and half plastic. On most modern machines it will snap on but older machines may have a screw mechanism for attaching.
If you haven’t purchased your sewing supplies yet then read my article on beginner sewing kit on a budget to find out the best basics to start with.
Step 1: Pin the Fabric
Pin your two pieces of fabric with the RIGHT sides together at the raw edge.
This means the right sides (correct sides or printed sides) will be facing each other. If you are using a plain fabric it may not have a right or wrong side. Other fabrics will be faded at the back so it will be obvious which is the right and wrong sides.
I like to use the vertical method of pinning as I find it faster to remove. This means the pins are placed vertically along the edge with the heads sticking out from the edge of the fabric. It is a personal preference which way you place the pins.
Once you get confident with sewing seams you will probably be able to sew a straight seam without pins.
Step 2: Set the Seam Allowance
Refer to your pattern instructions to find out what your seam allowance is.
This is the distance you will be sewing from the edge. Common seam allowances are 1/2 inch (12mm) or 5/8 inch (15mm).
If your pattern does not have a seam allowance (this is common for European patterns) you will need to add it yourself. Don’t worry, I have an entire article on seam allowance and how to add it. Read >> seam allowance
Place your fabric under the foot with the needle on the seam allowance line and hold the threads.
You should start at least 1/4 inch (6mm) from the edge so that the whole foot is on the fabric.
The reason you should hold the threads to the back is so they don’t get caught under the foot or in the machine. You will only be holding them to start and not the whole time you are sewing.
You don’t need to measure the seam allowance. Most machines will have markings on the metal plate or in front of the foot so you can align the edge of the fabric with the markings.
On this machine, the measurements are in inches on the metal at the back and you can see the millimeters on the front plastic.
Step 3: Backstitch
Set your stitch length on 2.5. This is a good average setting to test on your fabric. The width should be 0 since we are doing a straight stitch.
Still holding the threads, backstitch almost to the edge. This simply means you take a few stitches backward.
There is normally a button on the front of your machine to go backward. When the button is pressed in it sews backward and when released it sews forward.
Don’t go off the edge. Most likely, this backstitching will only be 3 or 4 stitches. This is enough.
Back stitching will stop the ends from unraveling, making your seam much stronger under stress.
Step 4: stitch Forwards
Stop backstitching, then release the threads in your fingers and start stitching forwards.
Start sewing forwards in a straight line along the seam allowance line. Use the guides in the needle plate to keep nice and straight.
Step 5: Backstitch the End
Backstitch the end of the seam as well.
Stop 1/4 inch (6mm) from the edge, press the back button and take a few stitches backward.
To remove the fabric from the machine, lift the foot and make sure the needle is up. Pull the fabric out and cut the threads.
If your needle is down, you can turn the handwheel on the side of the machine to slowly lift it up.
Step 6: Press
Open up your piece, press and there it is. A nice straight seam!
Pressing for sewing is slightly different from your regular ironing. Instead of dragging the iron along the seam, press up and down with medium pressure.
How to Sew a Seam | By Hand
I have a longer article on how to hand stitch a seam, but here I will give you a rundown on the best 2 methods.
Sewing a seam by hand can be done by using
- Running stitch
To sew a seam by hand you will need:
- 2 scraps of fabric.
- Thread – The best type of thread to use is a polyester thread that is designed for general purpose.
- Hand sewing needles – Universal needles are a general sewing needle and choose a needle size appropriate to your fabric.
METHOD 1: Running Stitch
Running stitch is a simple up and down stitch and if you are a complete beginner then this is going to be the best stitch for you.
Start by threading your needle with a double thread and knotting the end. If you have any trouble threading the needle read my article on how to thread a needle.
Piece through the fabric from the underside and take small up and down stitches. For sewing a seam your stitches should be no more than 1/4 inch (6mm) apart. The smaller the stitches, the stronger your seam will be.
METHOD 2: Backstitch
Once you have mastered the running stitch, you will want to upgrade to the backstitch. Backstitch is an extra-strong hand stitch suitable for hand-stitched seams.
Read the full blog tutorial >> how to backstitch
Here is a video from the Treasurie YouTube channel on how to backstitch.
How to Sew a Seam | Conclusion
Congratulations! You’ve sewn your first pieces and now know how to sew a seam.
With a little practice, you will now be ready to tackle your first sewing project and your first straight seam.
Go and have a practice on some scraps and tell me what you think. Any tips to help other beginners?