Three documents come up in every founder conversation about manufacturing: tech pack, spec sheet, and CAD. They’re not the same thing. They’re not interchangeable. Sending the wrong one to a factory delays your sample by 2 weeks. This is the clean breakdown.
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We’ve spec’d 2,000+ styles. We use all three. Here’s what each is, when each gets used, and which one a factory will actually accept.
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The one-line answer
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- Tech pack: the complete manufacturing document (12–30 pages, 9 components)
- Spec sheet: ONE section inside a tech pack — usually the points-of-measure table
- CAD: the vector flat sketch — ONE component inside a tech pack — produced in Adobe Illustrator
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Tech pack is the document. Spec sheet and CAD are components of it. Many of the “tech pack vs spec sheet” articles online get this wrong by treating them as alternatives. They’re not — one contains the others.
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What each one actually is
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Tech pack (the whole document)
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A tech pack is the 12–30 page technical document that lets a factory produce your garment without follow-up questions. We’ve covered the full breakdown in what is a tech pack, but the short version is nine components:
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- Cover and style summary
- Technical flat sketch (this IS the CAD)
- Bill of materials (BOM)
- Points of measure (this IS the spec sheet)
- Construction details
- Labelling spec
- Packaging spec
- Size grading
- Revisions log
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If a factory says “send me the tech pack,” they mean: send all nine of those. Not just the flat sketch. Not just the POM table. All of it.
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Spec sheet (one component)
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A spec sheet is a tabular document listing the measurements of a garment. Specifically, the points of measure (POMs) with their values at sample size, plus tolerances and sometimes grade rules. That’s it.
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Some industries use “spec sheet” more loosely to mean “spec’ed-out document” — which historically referred to the early version of what is now called a tech pack. That’s where the confusion comes from. In modern apparel manufacturing, “spec sheet” = the measurement table inside a tech pack.
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A spec sheet on its own is useful for:
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- Communicating sizing to a fit model
- QC checks at the factory (does this sample match the spec?)
- Brand-internal record keeping for finished styles
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A spec sheet on its own is NOT enough for:
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- Telling a factory how to construct the garment
- Sourcing fabrics or trims
- Communicating labelling, packaging, or finishing details
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If you send only a spec sheet to a factory, they’ll ask for everything else.
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CAD (the technical flat sketch)
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CAD stands for “computer-aided design,” and in apparel it specifically refers to the vector flat sketch of the garment. Produced in Adobe Illustrator (.ai format), CAD shows the garment as a flat, black-on-white technical drawing with all seams, closures, and panels visible.
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A CAD is what designers send each other when they want to communicate shape. It’s what a factory uses to understand the visual silhouette before reading the rest of the tech pack.
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CAD is useful for:
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- Communicating silhouette and design intent
- Marking up construction callouts (numbered details linked to a construction page)
- Sharing a quick visual with a fabric supplier or trim supplier
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CAD on its own is NOT enough for:
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- Production (no measurements, no construction details)
- Sampling (a factory can guess at sizes but won’t make a sample you want)
- Costing (no fabric specifications, no labour estimates possible)
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Why the three get confused
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Three reasons most founders mix these up:
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1. Old industry jargon overlaps. In the 1990s, “spec sheet” was often used loosely to mean what we now call a tech pack. Some senior designers still use the term that way. Younger factories and modern designers use “tech pack” for the full document.
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2. Software branding confuses things. Adobe Illustrator markets itself as a “CAD” tool for fashion. Tools like CLO3D and Browzwear market themselves as “3D CAD.” Some PLM tools call their output a “spec sheet.” The naming is inconsistent across vendors.
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3. Marketplace listings are imprecise. Fiverr designers will offer “tech packs” that are actually just flat sketches, or “spec sheets” that are actually full tech packs. The label often doesn’t match the deliverable. Always ask to see a sample of the work before paying.
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When in the workflow does each one happen
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Stage-by-stage breakdown of when each document gets used:
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1. Concept stage: you have nothing. Maybe a mood board, maybe a hand sketch on paper.
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2. Design lock: you commit to silhouette, closures, panels, seams. At this stage you might draw a quick CAD (flat sketch) to capture the design intent. But it’s a working draft, not yet final.
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3. Tech pack creation: you (or your designer) builds all 9 components. The CAD becomes the locked flat sketch on pages 4-5. The spec sheet (POMs) gets built on pages 8-9. The whole document = the tech pack.
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4. Quote stage: you send the tech pack to 3 factories. Each quotes against the SAME document so you can compare apples to apples.
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5. Sampling: the factory receives the tech pack and produces a first sample. They reference the CAD for visual, the spec sheet for sizing, the construction page for build, the BOM for fabric, etc.
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6. Production: the factory produces in bulk against the same tech pack. They use the spec sheet (POM table) as the QC reference at the end of every production run.
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7. Catalogue / record-keeping: brand archives the tech pack for future re-orders or factory switches.
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The CAD and spec sheet appear AT MULTIPLE STAGES of the workflow, but the tech pack is the master document that contains them both.
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Which one does the factory actually want?
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The answer is always the tech pack. Always. If a factory only asks for a CAD or a spec sheet, they’re either:
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- A small atelier that’s used to filling in the gaps themselves (you’ll pay for it later in sample errors)
- A friend/contact doing you a favour (which doesn’t scale)
- A factory operating on guesswork (which produces inconsistent results)
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A reputable factory will never accept a partial spec. They’ll send back a request for the full tech pack. If they don’t ask, they’re filling in the gaps with assumptions, and you won’t know until the sample is wrong.
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Common scenarios — which document for which job
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Scenario A: “Send me your spec for quoting”
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The factory wants the tech pack, not just the spec sheet. “Spec” here is shorthand for the whole document. Send the full tech pack.
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Scenario B: “Can I see your design quickly?”
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This is a CAD/flat sketch request. Send just the flat sketch (the CAD page from your tech pack). Factories sometimes use this to quickly assess complexity before committing time to a full quote.
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Scenario C: “We need to QC the sample”
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This is a spec sheet request. The factory wants the POM table so they can measure the sample against the spec. Send just the POM page from your tech pack (or the spec sheet if it lives separately).
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Scenario D: “What’s the construction?”
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This is a tech pack request. The construction page lives inside the tech pack. Send the full document because they’ll likely also want BOM, labelling, and packaging once they see construction.
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Scenario E: “Do you have a marker/pattern file?”
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This is NOT a tech pack request. Marker files and patterns are graded production files in DXF or .ASTM format, produced by a pattern maker. The tech pack tells the pattern maker what to build; the pattern maker produces the marker. Don’t confuse the two.
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What format to send each in
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| Document | Standard format | Software |
|---|---|---|
| Tech pack | PDF for sharing + Adobe Illustrator (.ai) source | Adobe Illustrator + spreadsheet integration |
| Spec sheet | Excel/Google Sheets, exported as PDF for sharing | Spreadsheet |
| CAD | Adobe Illustrator (.ai) — vector format | Adobe Illustrator |
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The .ai format matters because factories often need to mark up the file with corrections. PDF is fine for reading but not for editing. Always send both .ai and .pdf when sending a tech pack to a factory.
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Tools that produce each
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For tech packs: Adobe Illustrator + Google Sheets or Excel (for tables). Optionally, PLM software like Techpacker, Backbone, or BlueCherry for brands at 30+ styles per season.
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For spec sheets: just Excel or Google Sheets. No need for fancy software.
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For CADs: Adobe Illustrator. Some studios use Figma or Affinity Designer but factories prefer .ai. CLO3D and Browzwear produce 3D CADs (different format, for fit simulation).
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We’ve covered the full software comparison in our tech pack software post.
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What we send when we deliver a Fabrickly tech pack
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For every paying client, we deliver:
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- PDF version of the full tech pack (for easy sharing with factories)
- Editable Adobe Illustrator (.ai) source of the flat sketches + labelling layout
- Editable spreadsheet (.xlsx) of the BOM, POMs, and grading tables
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Three files, one folder. Factories can read the PDF or edit the .ai if they need to mark it up. Brands can update the spreadsheet without redoing the Illustrator work.
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This is the format every modern factory expects in 2026. Anyone who delivers “just a PDF” with no .ai source has locked you into them — you can’t update the spec without going back to them.
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Frequently asked
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Q: My factory only asks for a spec sheet. Is that enough?
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No. They’re filling in the gaps from experience or guessing. You’ll find out which when the sample comes back. Always send a full tech pack even if they don’t ask.
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Q: Can I send just a CAD to get a quote?
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Some factories will quote on a flat sketch alone, but the quote will be a wide range (±30%) because they don’t know fabric weight, MOQ, or construction complexity. Send the full tech pack for accurate quotes.
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Q: Is a spec sheet the same as a tech pack in some industries?
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In some American footwear and accessories sub-industries, “spec sheet” historically meant what apparel now calls “tech pack.” This is fading. Today, in mainstream apparel manufacturing, they are different documents.
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Q: Do I need separate CAD files for each colorway?
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No. The CAD itself is black-on-white. Colorways are documented in the BOM (which fabric/Pantone goes with which colorway). One CAD covers all colorways of the same style.
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Q: Can AI tools generate CADs?
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Not yet, at the production-ready level. AI is useful for inspiration and early sketches. The technical flat sketch with specific line weights (1.5pt outer, 0.75pt internal) and accurate seam mapping still requires a human in Adobe Illustrator.
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Q: How long does it take to build each one?
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A spec sheet (POM table) alone: 1-2 hours. A CAD (flat sketch) alone: 3-6 hours. A full tech pack: 8-12 hours for an experienced designer, 20-40 hours for a first-time founder.
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What to do next
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If you’ve been sending only spec sheets or only CADs to factories and wondering why samples come back wrong: that’s why. Build the full tech pack.
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Three paths:
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- Build it yourself using our free 14-page tech pack template plus our 9-step how-to guide. Budget 20-40 hours.
- Hire us to build it in 7 days from £349. We deliver PDF + .ai source + .xlsx spreadsheet. Get a quote.
- Hire a freelancer if you can vet 3 candidates with single-page test jobs first. Budget £100-£500 plus 1-2 revision rounds.
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Whatever path you take, send the FULL tech pack to factories. Don’t piecemeal it.
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— Hasebul, Fabrickly