Types of Seams: The Six ASTM Seam Classes
A seam is the line where two (or more) fabric pieces are joined by a series of stitches with a defined geometry. Seam choice affects a garment's quality, performance, and cost, so it is worth knowing the dimensions that describe a seam and the six standard classes defined by ASTM.
The three seam dimensions
Every seam has three dimensions, and each affects quality, performance, and cost:
- Length - the total distance the continuous run of stitches covers (e.g. a side seam or shoulder seam).
- Width (seam allowance) - measured from the cut edge of the fabric to the main stitch line.
- Depth - the thickness/compressibility of the seam, a major factor in appearance and comfort, driven by fabric weight, fabrication, and seam type.
Sign in to continue
Types of Seams: The Six ASTM Seam Classes
Create a free SpecForm account or sign in to open the Production Knowledge library. Full articles and their data visuals are included with any SpecForm plan.