International Standards for Sewing Seams: ISO, ASTM, and ABC Seams

What is a Standard?

A standard is a norm for specifications, procedures, and guidelines that can be adopted either in a region, a nation, or the whole world.

The ultimate goal of any standard is to ensure consistency to systems, services, and products. They help to improve the communication by setting up the basis for a mutual understanding.

Standards can be registered under international organizations such as ISO and ASTM International or not. Depending on their nature and their purpose, standards are voluntary or mandatory. For example, a voluntary standard is the use of the Pantone Code to specify a color shade. These codes are not registered under the ISO specifications, but we use them worldwide anyway.
On the other hand, Care Labelling for clothing and textile is mandatory in most countries.  So, there is a mandatory standard that we have to follow in order to sell our products.

ISO, ASTM, and the Standards

ISO (International Organization for Standardization) is an independent, non-governmental international organization that brings together International Standards. They certificate organizations for products, services, and processes.

ASTM International (former ASTM – American Society for Testing Materials), similar to ISO, is another organization that develops and publishes standards for materials, products, systems, and services (they are not the only ones that do this).

These organizations cover an immense and diverse range of subjects, from the Temperature for Geometrical Products to Units of Measurements and Social Responsibility of Corporations.

On the other hand, other companies are specialized in a specific matter. That is the case of Pantone, a company which exclusive subject is color. And they provide a code system to refer and identify different color shades.

Standards for Sewing Seams

ISO and ASTM share a similar type of standardization for sewing seams: same basis but different codes.
By contrast,
our code system (ABC Seams Code System) has a different foundation, a different structure, and a different type of coding. And, same as Pantone, our code system is not registered under the ISO and the ASTM regulations. 

What differentiates ABC Seams from ISO seams?

If you are an experienced designer or product developer, you will know that speaking the same language as your factory is essential. And by language, we mean the way you explain your designs, as this will determine how well (or not!) you receive the prototypes.

The 5 most important differences between ISO and ABC Seams.

1. Representation of seams (sketch or diagram):


“All seams are shown as sewn on a machine.
In the case of multiple operations, they are shown as sewn after the final operation” (*1) 
That is, the seam is represented according to the position of the fabric at the end of the last operation on the sewing machine.
The fabric handling steps after sewing are not considered in the seam sketch.

ABC Seams

The seam is represented as seen on the finished garment. And the right side of the seam is always shown facing up.

2. Classification:


“Seams are divided (…) according to the types and minimum number of components within the seam” (*1), classifying them according to the position of the fabrics at the time of sewing:

  1. Superimposed
  2. Lapped
  3. Bound
  4. Flat
  5. Ornamental
  6. Edge Finishing

ABC Seams

Seams are classified into 3 categories according to their main function:

  1. Construction
  2. Finishing
  3. Details

That makes their search much faster and easier. 

If you want to know more about seam classification, read this article: Seam Classification.

These are the two most important differences. But they are not the only ones.

3. Seam Codes

ISO codes may change with each revision. In contrast, ABC Seams codes never change regardless of the year.

4. Seam sketch understanding

Have you tried to use ISO / ASTM seams and felt frustrated because you don’t understand the sketches? Don’t get depressed, this is very common. Especially if you don’t know how to sew. To be able to interpret the ISO / ASTM seams, you must know how to sew. Because as we told you before, their seams are represented according to the position of the fabric at the last sewing operation.

However, to use ABC Seams you don’t need to know how to sew (although we do advise you to do so!!).
The only requirement for interpreting the ABC Seams sketches is that you know how the seams should look on the garment. You simply tell the factory what you want and they, as professionals, will know how to do it.

5. Seam sketch color

 Color does make a difference. Because unlike ISO and ASTM which represent their seams (including stitches) in black color, at ABC Seams we use different colors to differentiate the fabrics of the stitches.

Reference material:


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Book "101 Sewing Seams"
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ABC Seams

The new standards for inspiring, communicating and referring sewing seams.