Fundamentals of Sewing: Seams

Fundamentals of Sewing: Seams


Above are the two most commonly used types of seams in contemporary sewing, closed and open seams and they are essentially sewn in the same way but are named differently depending on how the seam allowance is dealt with.

Every other special seam finish will fit under one of these two broad categories. It is always important to plan the best seam finish before you finish the pattern so that you can ensure that you have left yourself enough space.

Steps 1-4 outline the basic steps of sewing any seam:

  1. Take two pieces of fabric where the seam allowance has been marked with a very small cut into the edge of the fabric.
  2. Place the pieces of fabric with right sides together and so that the edges and small seam allowance notches match up.
  3. Sew the two pieces of fabric together from the notch and parallel to the edge of the fabric. If you have a 1cm seam allowance then your stitching line will be 1cm away from the edge of the fabric. Most sewing machines have measurements marked on the metal plate as a guide, otherwise you can mark it on a piece of tape and stick it to the metal place, measuring from the needle to get your guide line.
  4. Unfold the two pieces away from each other so that the right side of the fabric is faced down and the stitching line runs down the centre. From this point you can go either way with your seam finish, you can either have it closed or open.
  5. CLOSED SEAM: Press the seam allowance to one side.
  6. OPEN SEAM: Press down the centre of the seam allowance so that the seam allowance goes equally to either side.

As discussed in the post on seam allowances in pattern making», seams are basically the lines where two pieces of fabric are joined by stitching. When used in the colour blocking trend it is good to know how the perfect seam lines are achieved so that the different blocks of fabric are able appear to be part of one continuous piece of fabric.

For many of the designers who have been using colour blocking recently they would be joining the different coloured panels together with open seams, allowing the fabric to sit flush and meaning that there is not too much bulk on one side of the seam. In some cases when you are looking at the collections you may come across panels with topstitching on only one side of the seamline. If this is the case then the seam has probably been pressed closed and then topstitched to make the seam allowance sit nice and flat to one side.


Jonathan Saunders, AW11, London. Images from»

Images of seams by The Cutting Class»

Recent Articles

The Rule of Thirds Applied to JW Anderson | The Cutting Class. Design features in different ratios will change how the proportions of the garment are perceived. AW20.
19 Feb 2020
The Rule of Thirds Applied to JW Anderson
JW Anderson, London, AW20. It can be a fun game (depending on your idea of "fun", of course) to look at the proportions of the looks when you are clicking...
Integrated Jewellery and Lingerie Details at Dion Lee | The Cutting Class. AW20, New York.
14 Feb 2020
Integrated Jewellery and Lingerie Details at Dion Lee
Dion Lee, AW20, New York. With fishnet inserts, cutouts, and corset-like closures the Dion Lee show for Autumn-Winter 2020 was peppered with references to lingerie. Custom-made jewellery and hardware also...
Craig Green Quilted Jacket Details | The Cutting Class. Details on pink SS20 jacket.
06 Feb 2020
Craig Green Quilted Jacket Details
Craig Green Quilted Jacket, SS20. You have to wonder if there is a psychological advantage to wearing a Craig Green quilted jacket. The quilted sections are like soft armour plates...