Beginner Sewing In collaboration with
Digital Pattern Library by Xandra Jane

Seams are the most basic way of joining two or more pieces of material together in garment construction. Seam allowance is added to patterns and once constructed, they usually face the inside of a garment, but this varies according to the type of seam used. 

Seams are also used to create shape and have an impact on the design of the garment. Some seams are used to strengthen parts of a garment (e.g. in corsetry) whilst others are there simply for design purposes.

When choosing the right seam for constructing a garment, there are some points to consider. Different fabrics and styles require different seams. You will find various types of seams to choose from and it is always possible to even create your own!

Basic Construction

Across this mini series in collaboration with Beginner Sewing, I will be introducing seams that are intended to be made using a sewing machine.

There are two ways of preparing a seam:

  • Use pins to hold your material in place.
  • Use a basting stitch along the stitch line.

Start the stitching process on the machine by taking a couple of stitches forward and then secure the stitching by going back. When coming to the end of the seam, repeat this process. This is called a backstitch or backtack and will secure the sewing line so your garment doesn’t unravel! 

Cut off and neaten any loose threads.

LESSON ONE – Open Seams


In today’s lesson we are going to familiarise ourselves with the most basic and common seam: the open seam, also referred to as a plain seam.

The open seam is often drafted with seam allowances ranging from 0.5-2.5cm

Basic Construction of a Straight Plain Seam

Place your fabric right sides together and sew a straight line of stitches. Your stitch length will vary depending on the textile you are using. 

As a general rule of thumb with wovens or if you are just starting out on some easy cotton, 2.5mm stitch length is a good average.

A top tip to aid you in maintaining a straight line is to focus on the edge of your fabric not your machine needle or foot. You can also mark your seam allowance on your foot plate with a bit of masking tape for added clarity.


You can press your seam open or to one side before neatening the edges. 

If you choose to press your seam to one side, we usually press towards the side seams or back of the garment for aesthetic purposes. 

Neatening a seam stops the fabric from fraying and also improves the aesthetics of the inside of your garment. If you are looking to sew to a high standard, you want your garment to look as beautiful on the inside as it does on the outside!

We will cover various finishes later in this series, they can include but are not limited to:

  • Overlocked finish
  • Bias bound finish (also known as a Hong Kong finish)
  • Zig-zag stitch finish

Sewing Curves

Once you have mastered a straight, open seam you can move on to practicing your curves! 

In relation to garment construction, curves can often be found on stress points (think armholes or necklines) and can sometimes benefit from a shorter stitch length to accommodate and distribute the stress more effectively when worn. 

Take your time when sewing curves and go slowly. Trust the machine to help you as you shift and guide the fabric. 

If you are sewing tight curves it is worthwhile familiarising yourself with how to pivot.

Stop sewing at the point where you need to rearrange your fabric and keep your needle in your work. Be careful to lift the machine foot allowing you to pivot your textile without disrupting your stitch line. Lower your machine foot and continue to sew. This will achieve a tight, neat and crisp line of stitches in those tricky areas!

To Clip or To Notch

Finally, before pressing a curved seam you will need to either notch or clip your seam allowance, being careful not to cut through your stitches.

We do this to achieve a nice smooth line once pressed and is one of the most basic tips when creating a beautiful finish on curved, plain seams.

Only clip your seam allowance on a garment once you are happy with the fit.

If your seam is concave, meaning it scoops inwards, you want to clip your seam allowance. This consists of regular snips into the allowance following along the curve 

If your seam is convex, meaning it rounds outwards, you want to notch your seam allowance. To do this, cut small triangular shapes from your allowance. This releases any tension on the curve and achieves a nice smooth line once pressed.

Finally, as with any seam looking professional and neat, you want to give them a good press. When pressing curved seams it is wise to invest in a tailor’s ham that provides a 3D surface to get into the corners and smooth out your work.

Keeping a Fashion File

I would advise starting your own fashion file to document your samples and developing skills. It is a great exercise to sharpen your knowledge and techniques and lovely to look back on in the future to see how far you have come with quality and craftsmanship!

Happy sewing.

About the Author:

I’m Alexandra (she/her) and I wear many hats: Fashion Entrepreneur, Designer, Pattern Cutter, Creative Consultant and teller of bad jokes. I am the founder of Digital Pattern Library, an online platform transforming unsure, unconfident sewists into self-aware, liberated creatives able to design and produce their own creations that fit like a glove and encourage body confidence.

Joan Mantini

About Joan Mantini

After several years of being the Facebook page owner at Beginner Sewing, I noticed there was a desperate need to have a single go-to spot for members to be able to find answers to their common questions, get some useful tips & tricks, as well as find reputable places to purchase sewing products online. Taking my role as a trade publication editor by day, and combining it with my knowledge of frequently requested beginner sewing advice, I created An outlet that gives new sewists a free digital magazine geared for entry level sewing as an extra bonus!

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