Do you know what are the types of seam finishes and why is it important to choose the proper one?
A seam allowance is the area of fabric that we add around each pattern with the purpose of allowing sewing the fabrics. Its width varies depending on the design, the type of seam, and the sewing machine/s used.
There are 5 types of finishing to apply to a seam allowance. Its selection will affect the performance, quality, aesthetic aspects, and cost of the garment.
Some of these finishes suit better than others depending on:
– the selected fabric: weight and properties
– the type of seam (its structure)
– the style/type of the garment: sportswear, ready-to-wear, high-end, etc.
– the part of the garment where it’s applied: cuffs, neckline, shoulders, etc.
The purposes of finishing a seam allowance are:
– avoid the edge from fraying
– stabilize the seam and maintain the shape
– give more resistance to the seam/area
– enhance the inner look of the garment
In this article, we will explore the 5 techniques that we can use to finish a seam allowance.
The goal is to give you relevant information to help you choose accurately each seam of your designs.
Types of Seam Allowance Finishes
1. Raw Edge
Technique: there is no sewing technique applied nor stitches.
– low cost
– poor quality/durability
– the edge may fray
– fabrics that do not fray easily
– low priced products
– lined garments
– seams with topstitch/es attaching the seam allowance to the fabric
– frayed edges
– bags and shoes
Notes: This option is not recommendable for fabrics that fray easily unless the fraying is the desired effect.
2. Edge Polished with Stitch
Technique: a stitch wraps the edge of the seam allowance.
– low cost (low time consuming)
– easy and fast to make
– this technique is not considered a clean finish
– most types of fabrics, especially fabrics that fray easily
– most types of clothing
– hems of knit garments
– edges of flowy skirts cut on the bias
– Serged Edge (overlock stitch along the edge): it is the most popular on construction seams due to it is cheap, easy to make, and resistant
– Cover Stitch: mostly applied on the hem of garments made of knit fabrics
– Flatlock Stitch: clean on both sides with an embroidery look. We will see it on active wear due to its soft touch and its resistance
– Zigzag Stitch: the 1-step version suits better on woven, and the 3-step version is commonly used on knit, especially for lingerie and underwear
Notes: If the backside of the seam is visible, such as the back neckline seam of a t-shirt, it will make the garment seem low quality.
3. Self-Enclosed Edge
Technique: the edge of the seam allowance is polished by folding at least one edge inwards.
– clean appearance and cost-effective
– it is considered a type of clean finishing
– mainly used on woven fabrics
– unlined jackets and accessories
– shoulder seam
– crotch seam of jeans
– cuff vent
Notes: The best-known seams within this group are French Seam, Welt Seam, and Double Fold Hem.
4. Edge Polished with a Trim
Technique: the edge of the seam allowance is wrapped or covered by a trimming (tape or binding).
– also known as Hong Kong Finishing
– the trim increases the strength and stabilizes the seam
– high-quality technique
– medium to high cost: the trim (tape/binding) increases its cost significantly. In addition, some variants of this group require more than 3 machine passes, which makes them even more expensive
– medium to heavyweight fabrics
– fabrics that fray easily
– high-quality garments
– unlined garments
– curved or bias cut edges
Notes: seam allowances of construction seams can be either open or sewn together. The second option highly increases the stretch resistance and strength.
5. Edge Covered with a Piece of Fabric
Technique: the seam allowance is covered with another piece of fabric: a facing, lining, or another piece of fabric.
– in contrast to the technique above (Edges Polished with a Trim), the piece of fabric covering the SA is also a part of the pattern (not a trimming)
– it gives more structure to the garment and reinforces the seam, helping it maintain its shape
– clean looking appearance
– low cost
– most types of fabrics
– lined garments
– necklines, collars, and lapels
– yokes and shoulders
– armholes of sleeveless garments
– pocket opening
– bags and shoes
Notes: It may be too thick and stiff for heavyweight fabrics.
– There are 5 techniques to polish a seam allowance:
1. Raw edge
2. Edge polished by stitching
4. Polish by trim
5. Covered by fabric
– The type of finishing will affect the performance, quality, appearance, and the cost of the garment
– The main goal is to avoid the edge from fraying. Other reasons can be make the seam stable and more resistant, and give a high-end touch to the inside of the garment.
– Its selection will depend on our needs: quality, durability, stability, stretch resistance, strength, appearance, budget, etc.
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