Tech Pack vs Spec Sheet Difference for Apparel Brands and Manufacturers
A garment can look simple on a mood board and still fail in production because one measurement, fabric detail, or stitching instruction was unclear. That is where technical documentation protects both the apparel brand and the manufacturer.
Two documents often get mixed up: the tech pack and the spec sheet. They are related, but they do different jobs.
A tech pack explains the complete garment design and construction. A spec sheet focuses on measurements, sizing, and selected production requirements. Manufacturers use both to quote accurately, make samples, check fit, and control bulk production.
This guide explains the practical difference between them, what each document should include, and what new clothing brands should prepare before approaching a custom or bulk apparel manufacturer such as ZOOKS.
What a tech pack is and why manufacturers use it
A tech pack is the main production document for a garment. It tells the manufacturer what to make, how to make it, what materials to use, and what quality details must be followed.
Think of it as the instruction manual for a product. If the garment is a hoodie, the tech pack should explain the silhouette, fabric, GSM, trims, stitching, print placement, label position, packing method, and measurement chart.
A strong tech pack supports the full garment development process, including:
Initial costing
Material sourcing
Prototype or fit sample development
Pattern making
Sampling revisions
Production approvals
Bulk manufacturing
Quality checking
For apparel brands, a tech pack reduces guesswork. For manufacturers, it provides a clear reference when estimating price, planning production, and checking whether the finished garment matches the approved design.
A tech pack usually includes several pages or sections. The level of detail can vary depending on the product. A basic oversized T-shirt may need fewer pages than a panelled jacket with lining, zips, embroidery, and multiple trims.
Typical information in a tech pack includes:
Style information
Style name, product category, season, collection name, style code, and version number.
Technical flats
Front, back, and side drawings that show garment shape, seams, pockets, panels, cuffs, collars, openings, and construction features.
Fabric details
Fabric type, composition, GSM, weave or knit type, stretch requirement, finish, shrinkage notes, and approved mill reference if available.
Colour details
Colour names, Pantone or TCX references where used, contrast colour placement, print or embroidery colours, and shade matching notes.
Trims and accessories
Buttons, zips, drawcords, eyelets, elastics, labels, tags, patches, tapes, rivets, and packaging items.
Stitching and construction details
Stitch type, seam width, topstitching, bartacks, overlock or flatlock instructions, reinforcement points, hem finish, pocket construction, and attachment methods.
Artwork and placement
Print files, embroidery details, logo size, placement measurements, technique, colour breakdown, and approval references.
Bill of materials
A list of all materials needed for the garment, often called a BOM.
Measurement specification
Points of measure, base size measurements, tolerance, and graded measurements across sizes.
Size chart
Finished garment measurements or body size references, depending on how the brand works.
Care and labelling
Wash care instructions, label content, country of origin notes where relevant, and placement of labels.
Packing instructions
Folding method, polybag size, carton packing, size ratio, barcode sticker placement, and shipment notes.
The tech pack is especially useful when the product needs repeat production. If a brand reorders the same polo shirt after six months, the tech pack allows the manufacturer to refer back to the approved details instead of rebuilding the product from memory.
What a garment spec sheet is
A garment spec sheet is a shorter technical document that records the garment’s measurements and selected specifications. It usually forms one part of a tech pack, but it can also be shared as a standalone document for simple production or fit-related communication.
The core purpose of a spec sheet is measurement clarity.
It tells the factory:
What size is being measured
Which points of measure are required
What the exact measurements are
What tolerance is allowed
How measurements should grade across sizes
For example, a T-shirt spec sheet may include:
Chest width at 2.5 cm below armhole
Shoulder width
Body length from high shoulder point
Sleeve length
Sleeve opening
Neck width
Neck drop
Bottom hem width
Armhole depth
A trouser spec sheet may include:
Waist relaxed and extended
Hip width
Thigh width
Front rise
Back rise
Inseam
Outseam
Knee width
Leg opening
The spec sheet may also include limited production details such as fabric GSM, colour, fabric composition, basic trim notes, and stitching comments. Still, it does not usually explain the full garment development process in the same way a tech pack does.
In sampling, the spec sheet helps the pattern maker and sample room achieve the intended fit. In bulk production, it helps the quality team check finished garments against approved measurements.
Spec sheets are especially valuable when a procurement team already has a sample garment and wants a manufacturer to copy its measurements with defined tolerances. They also help when a brand has approved fit but needs to produce the same garment in multiple colours or fabrics.
Tech pack vs spec sheet comparison
The phrase tech pack vs spec sheet can cause confusion because the two documents overlap. The easiest way to understand the difference is this: a tech pack covers the full garment, while a spec sheet focuses mainly on measurements and key specification points.
Area | Tech pack | Spec sheet |
Main purpose | Explains the complete garment design, materials, construction, artwork, trims, packing, and measurements | Communicates garment measurements, size grading, tolerances, and selected production requirements |
Scope | Broad and detailed | Narrow and measurement-focused |
Typical use | Product development, sampling, costing, production approval, quality control, repeat orders | Fit development, sample checking, bulk measurement control, production reference |
Includes technical flats | Usually yes | Usually no, unless added as reference |
Includes measurements | Yes, often as a measurement section or attached spec sheet | Yes, this is the main content |
Includes size chart | Usually yes | Usually yes, if multiple sizes are involved |
Includes fabric and GSM | Yes, with detailed fabric information | Sometimes, usually in brief form |
Includes colours and trims | Yes, with placement and quality details | Sometimes, if needed for production clarity |
Includes stitching and construction | Yes, in detail | Limited notes only |
Best for sampling | Yes, especially for new designs | Useful, but often not enough on its own |
Best for bulk production | Yes, after sample approval and final updates | Useful for measurement control during bulk production |
Can stand alone | Yes, if complete | Sometimes, for simple items or copy samples |
A manufacturer usually prefers a complete tech pack for a new garment. A spec sheet alone can work in some cases, but only when the product is simple and enough supporting information is available.
For example, a plain round-neck T-shirt may be quoted with a spec sheet, fabric GSM, colour reference, and clear sample images. A padded jacket with lining, zip pockets, quilting, shell fabric, branding, and trims needs a full tech pack.
What each document should include
The best format depends on the garment, but certain details should never be left vague. “Premium cotton”, “regular fit”, or “good stitching” are not production instructions. They mean different things to different people.
Clear documentation uses measurable, visible, and checkable information.
Information to include in a tech pack
A practical tech pack should cover the full garment from design to packing. For most apparel products, include the following:
Product overview
Style name
Style code
Product category
Season or collection
Version number and date
Sample status, such as first sample, fit sample, or pre-production sample
Technical drawings
Front and back flat sketches
Side view if needed
Inside view for lining or internal construction
Detail views for pockets, plackets, collars, cuffs, waistbands, or closures
Fabric information
Fabric composition, such as 100% cotton or cotton-polyester blend
Fabric structure, such as single jersey, fleece, twill, rib, interlock, or woven poplin
GSM
Stretch requirement if relevant
Fabric finish, such as brushed, enzyme washed, peach finish, compacted, or mercerised
Shrinkage or wash requirement where known
Colour information
Main body colour
Contrast colours
Pantone or approved colour standard if available
Shade band or approval process for bulk fabric
Trims and accessories
Neck label
Wash care label
Hang tag
Buttons
Zips
Drawcords
Eyelets
Elastic
Patches
Tapes
Packaging materials
Stitching and construction
Seam types
Stitch types
Stitch density if required
Hem finish
Reinforcement points
Bartack locations
Topstitch width
Seam allowance
Special finishes, such as flatlock seams or coverstitch hems
Artwork details
Print, embroidery, appliqué, patch, or heat transfer detail
Artwork size
Placement from fixed points
Colour references
File reference
Technique and finish
Measurement and size chart
Base size measurements
Graded measurements for other sizes
Points of measure
Tolerance
Fit notes
Packing and finishing
Thread trimming
Pressing
Folding method
Polybag packing
Carton ratio
Sticker or barcode placement if required
Information to include in a spec sheet
A spec sheet should be simple, clear, and consistent. Use one unit of measurement, usually centimetres for Indian and export production teams, unless the buyer requires inches.
Include:
Style and sample reference
Style name
Style code
Sample reference number
Base size
Date and version number
Points of measure
Clear measurement names
Simple sketches or reference points if needed
Measurement method, such as “measure flat across chest”
Base size measurements
Exact finished garment measurements for the sample size
Notes for relaxed and stretched measurements where needed
Size grading
Measurements for each size, such as XS to XXL
Grading increments between sizes
Tolerance
Accepted variation for each point of measure
Tighter tolerance for critical fit areas
Practical tolerance for areas affected by fabric stretch or wash
Key production notes
Fabric GSM
Shrinkage allowance
Wash or finish note
Critical stitching notes if these affect measurement or fit
A spec sheet should be easy for a quality checker to use on the production floor. If the team cannot measure a point consistently, the spec needs a clearer definition.
Which document is needed for sampling and bulk production
For sampling, manufacturers need enough information to create the correct first sample. A full tech pack is best because it explains the product design, fabric, measurements, construction, and trims in one place.
Without it, the sample room may make assumptions such as:
Using a similar but incorrect fabric GSM
Choosing a standard rib instead of the intended rib quality
Placing embroidery based on visual judgement
Using a common seam finish instead of the required construction
Creating a fit that matches factory standards rather than brand standards
For bulk production, the final approved tech pack and final spec sheet are both important. The tech pack confirms what to produce. The spec sheet helps control measurements during cutting, sewing, finishing, and final inspection.
A practical production flow looks like this:
Brand shares design brief, reference sample, sketches, or tech pack.
Manufacturer reviews feasibility, fabric, MOQ, trims, and costing.
First sample is developed.
Brand reviews fit, fabric, construction, and artwork.
Tech pack and spec sheet are updated after corrections.
Pre-production sample is approved.
Bulk production starts using the approved documents.
Quality checks compare production pieces against the approved sample and spec sheet.
Can a spec sheet be used without a full tech pack? Yes, in limited situations.
A standalone spec sheet may be enough when:
The garment is basic, such as a plain T-shirt, vest, or simple shorts
The brand provides an approved physical sample
Fabric quality, GSM, colour, trims, and construction are already confirmed
There is no complex print, embroidery, wash, or panelling
The manufacturer has made the same style before
A spec sheet is usually not enough when:
The product has custom construction
Fit is brand-specific
There are multiple fabrics or panels
Artwork placement must be exact
The garment uses custom trims
The product needs wash effects, lining, padding, or technical performance features
For new clothing brands, the safest approach is to share as much information as possible. If a formal tech pack is not ready, provide clear references and ask the manufacturer what else they need before sampling.
Useful starting material includes:
Front and back sketches or reference images
Physical sample if available
Target fabric and GSM
Size chart or desired fit sample
Colour references
Branding placement
Trim requirements
Expected order quantity
Target price range if relevant
Packaging needs
Any compliance or labelling requirements
ZOOKS, as a custom and bulk apparel manufacturer, can review available inputs and guide brands on what documentation is still needed before sampling. This is especially useful for startups that know the product they want but have not yet built a complete tech pack.
Common mistakes to avoid when preparing these documents
Most production issues do not come from one large error. They often come from small missing details that create different interpretations.
Using vague fabric descriptions
“Cotton fabric” is not enough. A 180 GSM single jersey and a 320 GSM fleece behave very differently. Mention fabric composition, knit or weave type, GSM, finish, and stretch requirement where relevant.
Sharing only inspiration images
Reference images help explain the look, but they do not replace measurements, construction details, or fabric specifications. A manufacturer cannot reliably copy fit and finish from images alone.
Missing tolerance values
Bulk production cannot match every measurement exactly. Tolerances tell the quality team what variation is acceptable. Without tolerance, a garment may be rejected unfairly or passed too loosely.
Not updating documents after sample corrections
If the fit sample changes from 70 cm body length to 72 cm, update the spec sheet. If the pocket position moves by 2 cm, update the tech pack. The approved sample and document must match.
Mixing body measurements and garment measurements
A body size chart shows the wearer’s body dimensions. A garment spec shows finished garment measurements. These are not the same. Garments need ease depending on fit, fabric, and style.
Ignoring shrinkage
Knitted cotton garments, washed garments, and fabrics with special finishes may change after wash or processing. If shrinkage matters, mention testing requirements or approved after-wash measurements.
Leaving trims undefined
Small trims affect cost, lead time, and appearance. Define zip type, button size, drawcord width, label material, elastic width, and colour where possible.
No version control
Manufacturers may receive several file versions during sampling. Use clear version numbers and dates so the team works from the latest approved document.
Clear technical documentation does not remove every production challenge, but it reduces avoidable mistakes. It helps brands explain expectations, helps manufacturers quote and plan accurately, and gives quality teams a fixed standard to check against.
For new apparel brands, the best next step is simple: prepare a clear tech pack if the design is new, and include a detailed spec sheet for measurements and sizing. If the product is basic and a full tech pack is not ready, share the closest possible information, including a reference sample, fabric GSM, size chart, colour details, trims, and construction notes.
If you are preparing a new custom or bulk apparel order, send your garment details, sketches, samples, or measurement sheet to ZOOKS for an enquiry. The team can review what you already have and help identify what is needed before sampling and production.
