What is a Notch?

In garment construction, a notch is a small mark or cut used to help correctly align pattern pieces when they are sewn together. Notches are usually positioned along the edge of a sewing pattern and transferred to the seam allowance of the fabric.

Notches act as matching points, helping ensure that different pieces of a garment are joined in the correct position.

The term notching can also describe cutting small V-shaped sections from the seam allowance of certain curved seams to remove excess fabric and help the finished curve sit smoothly.

What is a pattern notch?

A pattern notch is essentially a construction marker.

Garment patterns consist of multiple pieces that eventually need to fit together accurately. Notches provide reference points showing which sections should meet during assembly.

When two corresponding notches line up, the person sewing the garment knows the pieces are positioned correctly.

They're particularly useful when sewing:

• sleeves into armholes
• collars to necklines
• side seams
• waistbands
• panels
• pockets and other garment components

They're tiny marks doing a surprisingly important job.

Where are notches found?

Notches are marked along the cutting edge of a garment pattern and transferred to the fabric when the pattern is cut.

On the actual garment fabric, the notch should remain within the seam allowance.

That's important because the seam allowance will eventually sit inside the garment.

A notch should not extend through the stitching line and into the visible body of the finished garment.

What is seam allowance?

The seam allowance is the area of fabric between the raw cut edge and the line where the seam is sewn.

For example: RAW EDGE → SEAM ALLOWANCE → STITCHING LINE → GARMENT BODY

Because pattern notches are positioned within this extra fabric, they're hidden once the garment has been assembled.

Why are notches used?

Imagine trying to join two long or curved pieces of fabric with no reference points beyond their beginning and end.

It would be very easy for one section to stretch, shift or become incorrectly positioned.

Notches create intermediate matching points.

They help the sewer maintain the intended: position, alignment, shaping and distribution of fabric as the garment is assembled.

This is particularly important when two pattern pieces aren't identical in shape.

How do pattern notches work?

Matching notches are placed on pattern pieces that will eventually be sewn together.

For example, a sleeve pattern may contain notches corresponding with notches around the armhole of the bodice.

During assembly, those marks are matched.

That helps position the sleeve correctly rather than relying on someone to eyeball it and hope for the best, not exactly the preferred method in mass garment production. 😂

What do single and double notches mean?

Patterns can use different notch combinations to distinguish between pieces or positions.

For example, a pattern may use:

Single notch – often used as one matching reference.

Double notch – provides a different reference so similar-looking sections can be distinguished.

In commercial pattern conventions, single and double notches are often used to help distinguish areas such as the front and back of a sleeve or armhole, although exact conventions can vary.

The important point is that the notch system provides an unambiguous set of matching instructions.

Are notches cut into the garment?

Only slightly. When notches are physically cut into fabric, they should be small enough to remain safely within the seam allowance.

There are also different ways of transferring notch markings during garment production, so they don't always need to appear as obvious V-shaped cuts.

Once the seam has been sewn, the construction marks remain hidden inside the garment.

What does "notching a curve" mean?

Here's where the second meaning comes in.

Notching a curved seam allowance means removing small wedge-shaped sections of excess fabric after the seam has been sewn.

This is particularly useful on certain outward or convex curves.

When the garment is turned to the correct side, the seam allowance needs to spread around the curve.

Removing small wedges prevents the excess fabric from bunching and overlapping, helping the finished edge sit more smoothly.

Notching vs clipping

Notching

Notching removes small wedges of fabric from the seam allowance.

It is generally used where excess seam allowance would otherwise overlap and create bulk when the seam is turned.

Clipping

Clipping makes small cuts into the seam allowance without removing a wedge of fabric.

It's commonly used on inward or concave curves, where the seam allowance needs to spread apart when turned.

A simplified way to remember it is:

Outside/convex curve → notch to remove excess

Inside/concave curve → clip to allow spreading

Although, as always with garment construction, the precise technique depends on the seam and fabric.

Why notch curved seams?

Flat fabric behaves differently once it's sewn into a curve.

On some curved seams, the seam allowance can become compressed or overlap when the garment is turned.

That can create:

• bulk
• puckering
• uneven edges
• distorted curves

Removing carefully positioned notches allows the seam allowance to accommodate the curve more easily.

The result is a cleaner, smoother finished shape.

Are armholes always notched?

Whether a seam allowance needs to be notched, clipped, graded, trimmed or otherwise finished depends on the type of curve, construction method and fabric.

And importantly, an armhole can also contain pattern-matching notches before construction.

Same word. Different job.

Notches in collars and necklines

Notches and clipping are particularly relevant around curved or shaped garment components.

A collar and neckline may have pattern notches to ensure the collar is correctly positioned during assembly.

After sewing, the seam allowances may then require trimming, clipping or notching so the finished collar or neckline turns cleanly.

So a single garment component can potentially involve both meanings of the term.

Can you see pattern notches in a finished garment?

Normally, no.

Pattern notches and notched seam allowances are part of the garment's internal construction.

Once the garment has been sewn and finished correctly, they should be hidden inside seams, facings or lining.

They're part of the enormous amount of invisible construction sitting behind what looks like a very simple finished shirt, dress or jacket.

Are notches used in uniform manufacturing?

Absolutely.

Notches are a fundamental garment-production technique rather than a particular fashion feature.

They're used during the manufacture of everything from shirts and trousers to corporate dresses, jackets and workwear.

Accurate pattern alignment becomes especially important in commercial clothing production, where the same garment needs to be reproduced consistently across different sizes and production runs.