Tech Pack vs Spec Sheet: What Is the Difference and Which One Do You Need?

"Tech pack" and "spec sheet" are two of the most commonly confused terms in fashion manufacturing. Many designers, brands, and even factories use them interchangeably — but they refer to different documents with different scopes. THE SHORT ANSWER A spec sheet (specification sheet) contains only the measurement specifications for a garment — the size chart, points of measure, and tolerances. A tech pack (technical package) is a complete production document that includes the spec sheet plus the technical flat sketch, bill of materials, construction details, artwork placement, labelling instructions, and revision history. Every tech pack contains a spec sheet. A spec sheet is not a tech pack. THE SPEC SHEET IN DETAIL A spec sheet — also called a "measurement spec" or "size spec" — documents the physical dimensions of a finished garment across all sizes. A typical spec sheet contains: - Points of measure (POM): a numbered list of every location where the garment is measured (chest, waist, hip, sleeve length, collar height, etc.) - A diagram showing exactly where each measurement is taken on the garment - A size grid: each POM measured for each size (XS through XXL, or 0–20, or S/M/L) - Tolerances: the acceptable deviation for each measurement (e.g., chest ±1 cm) Spec sheets are used during: 1. Pre-production — to communicate size targets to the factory 2. Sample review — QC teams measure the sample and compare against the spec 3. Top-of-production inspection — confirming bulk production matches spec before shipment THE TECH PACK IN DETAIL A tech pack is the master document for a style. It contains every piece of information the factory needs to produce the garment correctly. Sections of a complete tech pack: 1. Cover page (style info, season, version number) 2. Technical flat sketch (front, back, detail callouts) 3. Bill of materials (fabric, trim, labels, hardware — each with colour codes and supplier references) 4. Construction details (seam type, stitch density, topstitch width, seam allowance) 5. Spec sheet (the measurement grid described above) 6. Colourway guide (Pantone references for each colourway) 7. Artwork/print/embroidery placement (dimensions, coordinates, file references) 8. Label and packaging instructions 9. Revision history The spec sheet is section 5. Without sections 1–4 and 6–9, the factory still has many unanswered questions about how to produce the garment. WHEN TO USE A SPEC SHEET ALONE A stand-alone spec sheet is appropriate when: - You are an established brand sending revised measurements to a factory that already has your full tech pack - You are conducting a fit review and only need to communicate measurement changes - You are working with a pattern maker who needs dimensions but not material or construction details - Your factory relationship is long-standing and they already know your construction standards WHEN YOU NEED A FULL TECH PACK A full tech pack is required when: - You are approaching a new factory with a new style - You are placing your first production order - The garment has complex construction (multiple fabrics, prints, special trims) - You need the factory to quote based on your exact specifications - You want a documented, version-controlled record of your design WHICH IS MORE COMMON IN THE INDUSTRY? In professional fashion brands, the tech pack is the standard. Sending only a spec sheet to a factory without construction details, BOM, and flat sketches is considered incomplete documentation and leads to expensive errors. New designers and startups often start with a spec sheet because it seems simpler, but quickly discover that factories ask for all the additional information anyway — it is better to provide a full tech pack upfront. SPEC SHEET TEMPLATES vs TECH PACK SOFTWARE Spec sheets can be created in Excel or Google Sheets using free templates. They are relatively simple tabular documents. Tech packs require more sophisticated tools because they include vector drawings, colour management, and multi-page layout. Professional options include: - ThreadPack — purpose-built web platform with canvas, BOM templates, measurement grids, and PDF export - Adobe Illustrator — industry-standard but requires design skill and manual formatting - Techpacker — a dedicated tech pack platform - Google Slides / PowerPoint — usable but not purpose-built; lacks measurement intelligence FREQUENTLY ASKED QUESTIONS Q: Can a factory produce a garment from a spec sheet alone? A: Technically yes, if they are copying an existing reference sample you provide alongside the spec. But without a tech pack, the factory is making significant assumptions about construction and materials, which leads to costly revisions. Q: What does "finished garment measurement" mean on a spec sheet? A: Finished garment measurement (FGM) is the measurement of the completed garment laid flat, after sewing. It is always larger than the body measurement by an amount called ease. A person with a 90 cm chest might wear a shirt with a 100 cm chest measurement — the 10 cm is the ease. Q: What is a "graded spec sheet"? A: A graded spec sheet shows measurements for every size in the range. Grading is the process of scaling a base size up and down to generate the full size run. A graded spec sheet is what factories need to cut markers (patterns) for production. Q: Is a tech pack or spec sheet legally binding? A: Neither is typically a legal contract on its own. The purchase order (PO) is the binding commercial document. However, the tech pack referenced in the PO forms the quality standard against which the factory's production is measured.