ABC Seams Code System (ASCS)
A visual language to identify, code and communicate sewing seams.
The ABC Seams Code System (ASCS) is designed to identify, code, and communicate sewing seams in a visual, precise, and technical way.
ASCS was created to enhance communication between designers, technicians, product developers, and manufacturing teams. It improves clarity, consistency, and efficiency in the technical documentation of garment development.
Who is it for?
- Technical designers and product developers
- Fashion students and educators
- Factories and production/inspection teams
- Sewing enthusiasts looking to elevate their projects, improve finishing quality, and master professional techniques
Ideal for brands aiming to:
- Ensure technical consistency between tech packs, samples, and production
- Reduce the number of prototypes needed per style
- Avoid misinterpretations in construction sheets and manufacturing processes
- Improve product quality from the early stages of development
Commercial use under license.
How does ASCS work?
Each seam type is represented by a unique visual diagram and a structured alphanumeric code that outlines its technical configuration.
The system is inspired by standards such as ISO 4916, but developed from designers’ perspective: more intuitive, visual, and practical.
Want to know more about this? Read our article: International Standards for Sewing Seams.
How to use ASCS?
Designers and product developers use the ABC Seams Code System (ASCS) to explain design details in their tech packs.
We offer tailored access for different types of users:
Fashion Brands
Teams can get a Multi-User License to access all our digital tools, including the complete Seam Code Library, eBooks and editable templates.
Ideal for companies that work with quality products or need to improve consistency.
Independent Professionals
Freelance designers, consultants and independent technicians can purchase the full collection of Seam JPGs for their technical tool kit.
Great for building tech packs quicker and keeping them clear and professional.
Students
Students whose institutions don’t have the Multi-User License can get access to over 150 seams for free in our Seam Gallery.
Browse by category, copy the seam diagram, and paste it directly into the tech packs.
Perfect for learning.
Selecting the right seam in 3 Steps
Step 1: Define the CATEGORY
What’s the purpose of the seam in this garment? Decide if you’re working with a:
- Construction seam: joins panels and provides structure (e.g. side seam, crotch, armhole)
- Finish seam: cleans or closes edges (e.g. hems, necklines, plackets)
- Detail seam: adds shape, design, or functionality (e.g. darts, decorative topstitching, pintucks)
Step 2: Choose the seam STRUCTURE
Think about the garment, its final use, and the area where the seam will be applied. Does it need a clean finish? Stretch resistance? Flexibility? Reinforcement?
Consider the stress direction, fabric type, and the finish you’re aiming for. These elements will guide you toward the most appropriate seam structure (or seam type).
For example, a French seam (C010) for side seams in loose sheer garments, a welt seam (C110) for high-stress areas like jeans’ crotches, a felt seam (C100) for lined jackets, or a bound seam (C101) for unlined jackets.
Step 3: Select STITCH and/or TOPSTITCH
Both components define the technical performance and visual result of the seam.
- Stitch: the construction method used to join fabrics (e.g. lockstitch, overlock, chainstitch)
- Topstitch: visible stitching on the right side, number of rows and position (e.g. single, double, decorative)
You can start with either one, depending on your technical or design priorities.
Why do you want to use ASCS?
- Enhance communication between creative, technical, and production teams
- Save time and reduce errors during product development
- Establish a consistent foundation for tech packs
- Promote technical learning in schools and among junior teams
- It adapts to any garment type or level of detail
Resources and Tools Available
Technical Books (digital and print)
- 101 Sewing Seams — The Most Used Seams by Fashion Designers
A visual catalogue of the 101 most common seams used in fashion design. - Sewing Seams for Tech Packs — A Visual Guide to Design Clothing
27 illustrated cards to build complete and professional tech packs. - Strong Seams — The Catalogue to Design Durable Clothing
A seam catalogue focused on reinforced constructions and durability.
Other digital resources
- JPG Seams — Digital Library of Seams in JPG format
A downloadable library with 570+ seam illustrations to use on tech packs. Compatible with Illustrator, Photoshop, and Excel.
- My Sewing Seams Collection — Printable Sewing Cards
PDF-format cards to build your own illustrated seam reference library.
Multi-User Licenses for Brands & Universities
We offer multi-user licenses for fashion schools and brands looking to implement ASCS in their daily workflows.
Want to integrate the system into your classroom or team? More info here
Free Resources
- Seam Gallery
A free visual library of seam diagrams that designers and product developers can browse, copy, and paste into tech packs to explain construction details.
- Freebies
Downloadable guides, seam classification charts, and technical freebies.
Join our private Fresh News club to receive updates on what is happening at ABC Seams, from new seams and articles to quizzes and exclusive material.
