Types of Seams - Best Guide to Sewing Seams

Learn all about the different types of seams. There really is a seam for every season of clothing and every variety of fabric. Knowing about the different types of seams, and their suitability for different projects, helps with deciding what seam type to use for your sewing requirements.

Types of Seams

Firstly, seams can be divided into different classes depending on their use in the production of a garment.  These classes are determined by the following descriptions. There are many types of seams and each variety has a different technique and finishing process.

1. Position of the Seam - A seam can be determined by the place it takes on the garment.  Back seams, side seams, center front seams, curved seams, facing and collar seams, as well as yoke seams all, serve different purposes.
2. The Finished Edges of the Seam - The seam finish, making it a closed seam, or an open seam, with a finishing edge is part of the different seam types.
3. The Fabric Needs - This is a very important aspect of choosing the type of seam. Depending on the weight and bulk of the fabric, you will require different seam finishes.  Soft chiffons for example will not need the same type of seam as heavy types of denim or tweed fabrics.
4. The Function of the Garment - Making hardwearing work clothes as opposed to soft lingerie will help to determine the type of seams you want to use.

Once you have decided on the purpose, place and suitability to your fabric, then look at the following seam types to choose the right seam for the job.

More About the Types of Seams

Knowing the different types of seams helps you select the right seam for the right fabric and position of the seam in the garment. Some are easy, some are moderately easy, and some are more difficult. If you have some time on your hands, making a folder of samples with some notes. 

The actual seams, together with their finish, follow their own classification order as well.  They are seen as plain seams, open seams, closed seams, decorative seams, and seams suited to delicate fabrics or hardwearing fabrics. The right seam will make all the difference to what you are trying to achieve. 

Bound Seams

Hong Kong finish seams and bias bound seams are very professional-looking types of seams and are perfect for unlined jackets in thicker fabrics. Cut on the diagonal, the bias tape is a beautiful and elegant contrast to the fabric of the garment.  Bound seams usually bind each side of the seam in a contrasting fabric.

How to Sew Bias Bound Seams (Standard):

• Press ½ inch (12mm) single fold bias tape in half with the wrong sides toghether.
• Slip the bias tape over the edge of the seam.
• Stitch along the edge.

How to Sew Hong Kong Finished Seams

• Open up one side of the bias tape.
• Put it right sides together along the seam allowance. Stitch in the crease.
• Fold the bias tape to the back.
• On the front, stitch in the ditch.

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Closed Seams

Closed seams have the edges of the seam allowances finished together. They are considered one of the strongest types of seams. The seam allowance is pressed to one side or completely encased, as in French seams. Closed seams can be finished with a zig-zag stitch, pinking shears, or a serger.

Types of Closed Seams

• Zig-Zag
• Overcast
• French
• Bound Welt
• Lapped
• Run and Fell

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Counter Seams

The counter seam is a strong three-layered seam.  The seam allowance on the right side is turned under on the upper right side and over on the left side.  The two seam allowances turned over are then interlocked and edge-stitched to form a firm strong seam.

Decorative Seams

Decorative topstitching, in a contrasting color, adds interesting variations to a seam.  A plain seam or a welt seam or any seam showing stitching on the outside lends itself to some form of decorative stitching.

• Bound seams can be very decorative if a contrasting binding is used.  Jackets that are not lined and have contrasting bound seams on the inside look very fashionable. 
• Piped seams add texture to the seam and a tailored finish to a yoke seam or to pockets.  Piped seams make great casings for boning and inserting the stiffening for corsets.
• Slot seams add a flash of color in a contrast fabric.  They add strength to sporting gear and are an attractive addition to the side seam of tracksuit pants for example.

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Double Stitched Seam

A double-stitched seam is the same as the plain seam, but two rows of stitching are used to complete the seam. The seam presses to the side. The extra row of stitching helps to prevent fraying but is not as good as a proper seam finish. You may need an additional seam finishing for fabrics that fray easily. Double topstitched seams are pressed open.  In this seam, the seam is stitched and then pressed open and the seam allowance is stitched down on either side.

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Faced Seams

A common type of seam on necklines and armholes of garments is facing. The facing is cut a couple of inches wide and stitched and turned to the inside of the garment. It is usually of a matching fabric and may need interfacing to add a little stiffness. Learn about sewing facings.

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Flat Felled Seams

A flat felled seam is a very hard-wearing seam and ideal for clothing needing a tough seam like jeans and winter shirts.  It is also known as a run and fell seam. A hemmed fell stitched seam is useful for lingerie and the seam is made in the same way as the flat felled seam, but the second row of stitches are hemmed instead of machine stitched.

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French Seams

French seams are types of seams traditionally used for fine fabrics that fray easily and are a closed seam. The raw edges of the seam are completely enclosed in a neat double seam. It is easy to sew but starts with the wrong sides together to sew the first part of the seam. The raw edges are trimmed and enclosed in the seam.  The seam is turned to sew the right sides together.  The second row of plain stitches is sewn and the raw edges are enclosed in the seam.

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Graded Seams

Grading seams reduce bulk in garments with multiple layers or thick fabrics. The seam allowances of fabric are cut back in layers. These types of seams are suitable for winter fabrics where the seam will be pressed to one side. Each layer of seam allowance is cut ⅛ inch (3mm) smaller than the underneath layer. This means you may have to widen the seam allowance where you have 4 or more layers. Grading is particularly useful when you have intersecting seams such as in the underarm area of shirts.

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Hairline Seams

The hairline seam is a very fine seam because the seam allowance is trimmed down to almost a hair’s breadth.  This seam is popular for the joining of collars where the fabric is fine and the seam could show through.  A trimmed hairline seam looks good on collars and cuffs with fine transparent fabrics.

Handstitched Seams

When you don't have access to a sewing machine, hand-stitched types of seams can be convenient. Learning how to hand sew is simple, and all you need is a needle and thread. The most common hand stitches to use for seams are the running stitch and backstitch. The running stitch is the easiest with its simple up and down motion. With both of these stitches, the smaller your stitches, the stronger your seam will be.

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Lapped Seams

The lapped seam is a great seam for joining fabrics together to avoid bulky seam finishes.  The lapped seam is specifically used for fabrics that do not fray because the raw edges are not enclosed. Typical fabrics where you would use a lapped seam include felt, leather and vinyl.

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Open Seams

Open seams once stitched, have the seam allowance pressed open. Each side can be neatened by pinking, zigzag, serger or bias. The open seam can be finished with a turned edge finish on either side if your machine does not have any different stitches. This is known as a clean finish edge seam.

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Pinked Seams

Pinked seams use serrated pinking sears to finish the edges. The seam allowances can either be pressed open or together to one side. Pinking is a great method for fabrics that do not fray much or items that will only occasionally be worn or washed.

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Piped Seams

Corded or piped types of seams are decorative and great for a piped edge in upholstery or in a trim for a garment. Learn how to make piping and all about sewing piping including corners, overlapping, and finishing.

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Plain Seams

Plain seams are the most simple of all the seams. The single plain seam is simply two pieces of fabric sewn together with a plain row of straight stitching. Right sides together and stitch a line along the seam line leaving a seam allowance that may need neatening.  This seam can be pressed open or kept closed - it is entirely up to you as the designer of the garment and the finish you are looking for. If you are lining your garment then it is not necessary to finish the seam edges. The plain seam is well suited to be completed by hand using a simple backstitch or by machine.

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Princess Seams

Princess Seams are challenging because they are sewn along the curve of the bust on the bodice.  They can be pressed open or a French seam finish can be used.

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Puckered Seams

These seams are in a class of their own because they are the seam finish you want to avoid.  If you should find your seam is puckered there are a number of reasons to investigate and troubleshoot this outcome of your particular seam.  Seams are not generally intended to pucker.

Serged Seam

A serged seam is considered one of the easiest and strongest seams. The seam allowances can be serged separately or together.

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Slot Seams

Slot seams have a pop of color peeking out from the edges of the seam. These types of seams are used for decorative purposes and are considered a durable and easy to sew seam. These seams are used on shirts and down the sides of pants.

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Welt Seams

The welt seam is a version of the flat fell seam and sometimes called a mock flat-fell seam. It is a closed seam, but the raw edges of the seam allowance are just kept flat on the wrong side. They can be neatened or just stitched down flat. A welt seam uses one line of stitching to stitch the fabric together and one line of stitching to stitch the seam allowance down.  The fabric of one side of the seam allowance is trimmed to reduce the bulk in the seam.

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Types of Seams and Uses Chart

Here is a chart for the types of seams and their recommended uses.

TYPE	DIFFICULTY	FABRICS	GARMENTS	FINISHING
Plain Seam	Very Easy	Most cotton fabrics. Light weight linen.	Dresses, blouses, loose fitting day wear.	Unfinished if in a lined garment. Or pinking, zigzag etc.
Plain Seam (Single Stitch)	Easy	Cottons and linen, light weights.	Easy day wear, simple seams in a lined jacket.	The extra line of stitching finishes the seam.
Plain Seam (Double Topstitch)	Easy	Cottons and linen and slightly heavier fabrics.	Useful for some soft furnishings and day wear.	The double stitching is the finishing method.
Lapped Seam	Easy	Fabrics that do not fray.	Garments not needing a structured seam.	No finished edges the fabric does not fray.
French Seam	Easy	Soft light weight fabrics. Chiffons and lawn 100% light cottons.	A variety of soft light dresses, blouses, lingerie and evening wear.	The raw edge is enclosed in the seam no need to finish the edges.
Butt Seam	Easy	Medium weight to soft fabrics.	Useful for a hand stitched seam not needing too much strength.	Neaten seam edges beforehand if necessary.
Flat Felled or Run and Fell Seam	Easy	Hard wearing denims, thick cottons, drill.	Outdoor clothing, play clothes and work clothes denim trousers.	The edges are enclosed in the seam with a flat edge and edge stitching.
Hemmed Fell	Easy	Soft light fabrics, cottons and fabrics easy to add hemmed finish.	Soft casual light garments needing a neat finish and a seam that will not fray.	The edges are trimmed and enclosed in the seam that is hand stitched to complete.
Hand Stitched	Easy	Firm cottons easy to hand stitch fabrics.	Garments that do not need heavy washing.	Neatening would be hand stitched.
Mock Flat Fell or Welt seam	Medium	Hard wearing fabrics. Denim.	Garments needing to be hardwearing.	Neatening is included in the seam or welt.
Bound seam	Medium	Medium to hard wearing fabrics.	A strong seam for unlined jackets.	The edges are bound with bias binding.
Slot Seam	Medium	Cottons and medium weight fabric.	Sporty items needing strong seams and some decorative insert.	Neatening included in the seam.
Lapped Seam Tucked	Difficult	Heavier fabrics needing a strong seam.	Outdoor clothing men’s shirts and trousers.	Neatening included.
Corded or Piped	Difficult	Medium to light cottons not for heavy fabrics	A decorative seam adds trims and casing for piping.	Neatening included in the process.
Princess Seams	Difficult	Light to medium weight fabrics with tricky curves to take into account.	Fashion wear for ladies to create a beautiful figure shape.	May need neatening depending on the open or closed seam approach.
Hong Kong Finish.	Difficult	Heavier weight fabrics used in tailored clothing.	Suits, jackets, clothing needing a fashionable finish.	The bias tape of self-made tape is the neatening.

Types of Seams - In Conclusion

In the overall scheme of things, there are different seam finishes and styles to consider.  Patterns do not always give a recommended seam to use however, by trying out the different types of seams and seeing how they work there is an understanding that will develope between the seamstress and the seam.