Seams and Seam Finishes – SS1 Fashion and Garment Making Lesson Note (Second Term)

A seam is the line of stitching that joins two pieces of fabric. Common seams are the plain seam, the French seam, the overlaid seam and the run-and-fell seam. Raw edges inside a seam fray, so they are neatened with a seam finish such as pinking, edge stitching, hand overcasting, overlocking or zigzag stitching.

Behavioural objectives

By the end of the lesson, students should be able to:

1. Describe how to make a plain seam and a French seam.
2. State where the plain seam, French seam, overlaid seam and run-and-fell seam are used.
3. Explain why the raw edges of a seam need to be finished.
4. Name and describe the pinked, edge stitched, hand overcast, overlocked and zigzag finishes.

What are the common types of seam?

The plain seam (the foundation)

The plain seam is the most basic seam. Almost every garment you own started with this. It is simple, quick, and stays flat.

• How to make it: Put the “Right Sides” (the pretty sides) of the fabric together and sew a straight line, usually 1.5cm from the edge.
• The result: When you open the fabric, the stitches are hidden on the inside.
• Where to use it: Side seams of skirts, trousers and blouses.
• Important step: After sewing, you must “press the seam open” with an iron so it lies perfectly flat against the body.

The French seam (the “clean” seam)

The French seam is a bit of “magic”. It is a “seam within a seam”. It completely hides the raw edges of the fabric inside the seam itself.

• How to make it: Start by putting the “Wrong Sides” together. Sew a tiny seam, trim the edges, flip the fabric so the “Right Sides” are together, and sew again.
• Why use it?
  1. It is very strong.
  2. It looks very neat (no raw edges visible).
  3. It is perfect for thin or see-through fabrics like chiffon or silk, where a messy edge would show through to the outside.
• Note: It is not good for thick fabrics like denim because it becomes too bulky.

Other common seams

Depending on the style of the cloth, you might use these:

1. Overlaid (lapped) seam: One piece of fabric is folded and laid on top of another, then stitched down. This is common for attaching yokes on shirts or lace onto a dress.
2. Run-and-fell seam: You see this on the inside of your jeans. It is very flat and incredibly strong. It has two rows of visible stitching on the outside.

Why do we need seam finishes?

If you leave the edges of a plain seam “raw” (untouched), the threads will start to pull out (fray) every time you wash the garment. Eventually, the whole seam will rip open.

Seam finishing is the process of neatening those raw edges.

Types of finishes

• Pinked finish: Using pinking shears (zigzag scissors) to cut the edge. This is the fastest way, but it only works on fabrics that don’t fray easily.
• Edge stitching: Folding the raw edge under a tiny bit and sewing a straight line.
• Hand overcasting: Using a needle and thread to make diagonal loops over the edge. This is great if you don’t have a machine.

What are professional finishes?

In modern fashion, the “Gold Standard” for finishing is overlocking (sometimes called serging).

• The overlocker machine: This is a special machine that uses 3 or 4 threads at once. As it sews, it trims the excess fabric with a built-in knife and wraps the threads around the edge in a “web” pattern.
• Zigzag finish: If you don’t have an overlocker, you can use the zigzag stitch on a regular domestic machine. You sew right on the edge of the fabric so the “zig” goes into the cloth and the “zag” goes over the edge.

Teacher’s tip: A “Master Tailor” is known by the inside of their clothes, not just the outside. If the inside is full of hanging threads and messy seams, the garment isn’t finished!

Evaluation

1. Describe the steps for making a plain seam.
2. Why is the French seam suitable for chiffon but not for denim?
3. Name the seam you would see on the inside of jeans and state one feature of it.
4. What happens to a plain seam if its raw edges are not finished?
5. Give two ways of finishing a seam if you do not have an overlocker.

Assignment

Write short notes on the French seam and the overlocked finish. For each one, say how it is made and when it is used.