01
Technical Communication
Specification sheets (tech packs)
A tech pack is the controlled instruction set used to develop, quote, sample and manufacture one style. It must let a patternmaker, sample room, supplier or quality team understand the current design without relying on memory or an informal message. Start with a cover page identifying brand, season, style name and number, product category, sample size, intended size range, owner, date and revision. Add accurate front and back technical flats, enlarged detail views, a colourway page, bill of materials, measurement specification, construction pages, artwork or placement information, labels, packaging and required testing. FIT’s Technical Design programme explicitly joins pattern development, construction, fitting and the creation of a Technical Specifications Packet, while its current technical-design courses use industry terminology, digital imaging and software to build full tech packages.[1][2]
Make the pack precise, visual and revision-controlled. Give every component a code that is shared by the bill of materials and callouts; specify supplier reference, composition, colour, placement, quantity and approved substitute rather than writing “button” or “lining.” Use one measurement unit consistently and state it. Separate a requested design change from an approved production instruction, record sample comments against photographs or point numbers, and retain a revision log showing what changed, by whom and when. Remove obsolete instructions or mark them clearly as superseded. A tech pack is complete only when its sketches, materials, dimensions and construction agree with one another and with the approved physical or digital sample.
Practice
Create a development tech pack for a lined shirt or jacket: cover sheet, front and back flats, four detail callouts, coded bill of materials, colourway, measurement page, construction page and revision log.
Checkpoint
Every component and instruction must be traceable across the pack, units and sample size must be stated, no page may contradict another, and a peer must be able to identify the latest approved revision without explanation.
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Measurement charts
A production measurement chart defines how the finished garment will be evaluated. Distinguish body measurements, which describe the intended wearer, from garment measurements, which include design ease, functional ease and material behaviour. ISO 8559-1 provides anthropometric definitions and measurement principles for creating body-size and shape profiles, while ISO 8559-3 explains how body-measurement tables and intervals can be developed from population data for ready-to-wear sizing.[3][4] Use these as a consistent foundation, then define product-specific finished measurements from the approved fit, not by copying an unrelated brand’s size chart.
Assign each point of measure a stable ID, an unambiguous name, a diagram and a written method stating the garment position, fastening state, edge or landmark, and whether the value is full, half or one-side only. Record the base-size specification, grade rule or size values, tolerance and sample result in the same unit. Condition, relax and lay the garment consistently before measuring; close required fastenings, align seams without stretching and use the same calibrated tool. Tolerance is an acceptable production range, not additional ease: set it according to product function, material stability, process capability and the effect of the dimension on fit. Investigate related measurements together—for example, chest, across-front, across-back and armhole—because one isolated pass can conceal a distorted balance.
Practice
Develop a 15-point chart for a button-front shirt in five sizes. Include diagrams, written measuring methods, base specifications, grade values and tolerances, then measure two samples independently.
Checkpoint
Two trained measurers must reproduce each result within the stated tolerance, all grade increments must reconcile across sizes, and garment dimensions must provide the intended ease over the defined body profile.
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Construction details
Construction details explain how components are assembled and finished, not merely where visible lines appear. Use enlarged callouts, sections or exploded views for collars, plackets, pockets, waistbands, closures, hems, lining joins and reinforcement. For every operation, state seam and stitch type, seam allowance, stitch density, thread, needle or specialist requirement where relevant, edge finish, pressing direction, topstitch distance and start or stop points. Identify interfacing, stay tape, elastic, binding and reinforcement by code and show their exact extent. ASTM D6193 classifies stitch and seam types and stresses that strength, elasticity, durability, security and appearance must be balanced with fabric properties and end use.[5]
Specify performance rather than relying on vague phrases such as “clean finish” or “standard seam.” A stretch junction needs compatible elasticity; a pocket opening may need bartacks or another validated reinforcement; a sheer seam requires controlled opacity and trimming; and a bulky intersection needs an achievable layer sequence. Number operations when assembly order affects access or quality. Test the intended fabric, thread and machinery in a seam library, then wash, stretch, press or wear-test the sample as appropriate. Update the drawing and written instruction together after every approved change. The final construction page must match the pattern’s seam allowances, notches and internal marks.
Practice
Prepare six construction callouts for one garment and sew three representative samples: a structural seam, a finished edge and a reinforced opening. Record materials, settings, sequence and test results.
Checkpoint
A second maker must reproduce the details from the instructions, seam codes and allowances must match the pattern, and each sample must meet stated appearance and performance criteria after the selected test.
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02
Pattern Release
Production-ready patterns
A production-ready pattern is the approved geometry and manufacturing information from which consistent cut parts can be made. Release it only after the base-size fit, finished measurements, construction method and material behaviour have been confirmed. Every piece needs a unique name or number, style, base size, revision, fabric or component group, cut quantity, grain line, cut-on-fold or pair instruction and nap or one-way restriction. Add the approved seam and hem allowances, notches, drill or punch marks, internal construction lines, balance marks and placement guides. FIT’s patternmaking curriculum links accurate specifications to fit and balance, while its technical-design courses focus directly on production-ready woven patterns, graded specifications and marker preparation.[6][2]
Audit the pattern as a complete set. Walk every joining seam along its stitching line, accounting for ease, gathers, pleats and turn-of-cloth; true corners and intersections with seam allowance applied; verify mirrored parts, closure extensions, hem depths and placement marks; and compare finished pattern measurements with the tech-pack specification. Grade from an approved base and inspect every size at curves, notches and seam partners rather than assuming the rule applied correctly. Plot or print a scale test after export and confirm units when exchanging DXF or other formats. Lectra describes production pattern development as a workflow in which linked geometry, annotations and collaborative review protect data consistency and product quality.[7] Lock the released revision and route every later change through documented approval.
Practice
Prepare and audit a production pattern set for a collared shirt or lined skirt. Walk all seams, reconcile finished measurements, grade three sizes and export or plot one scale-controlled release set.
Checkpoint
No piece or annotation may be missing, corresponding seams and notches must match in every checked size, the plotted scale must be exact, and pattern, tech pack and approved sample must carry the same revision.
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03
Cost & Cutting Control
Cost estimation
A garment cost estimate converts design and production assumptions into a transparent unit cost. Create a preliminary cost while options are still open, revise it when materials, marker and operation sequence are confirmed, and compare it with actual cost after production. Build the estimate from main fabric and lining consumption, purchase price and expected loss; trims and packaging by quantity; direct labour from the operation breakdown and agreed rate; wash, print, embroidery or specialist processing; testing, inspection, development amortisation, overhead, freight, insurance, duties and commissions where applicable. State currency, exchange-rate date, order quantity, supplier terms and Incoterm or delivery basis so totals can be compared meaningfully. FIT’s Product Costing curriculum applies cost-accounting and industrial-engineering methods to estimating, capturing and assigning apparel costs and analysing variance between estimated standards and actual results.[8]
Keep facts separate from assumptions. A cheaper quoted fabric may create higher consumption, minimum-order exposure, defect loss or freight; a simplified seam may reduce labour but fail quality; and a small order may spread fixed development charges over too few units. Calculate cost impact before approving a design change and run quantity, material-price and exchange-rate scenarios. Distinguish markup from gross margin: markup is profit divided by cost, while gross margin is selling price minus cost divided by selling price. Compare the result with the target price architecture, but never force the target by deleting necessary labour, quality control or compliance. Record planned-versus-actual variance by category so the next estimate improves.
Practice
Cost one garment at two order quantities and with two material options. Show every unit, rate, allowance and assumption, calculate the target wholesale or retail scenario, and identify the three largest cost drivers.
Checkpoint
All totals must recalculate from visible inputs, consumption must agree with the marker estimate, fixed and variable costs must be distinguishable, and each scenario must state its currency, quantity, terms and risk.
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Marker planning
A marker is the controlled arrangement of all required pattern pieces within the usable fabric width for a stated size ratio and cutting order. Confirm the released pattern revision, sizes, quantities, fabric width, spreading mode and material category before nesting. Apply grain tolerance, nap or one-way direction, face-up or face-to-face rules, pair requirements, checks or stripe matching, motif placement, tubular or open-width conditions, buffer distances and any prohibition on rotation. Include every shell, lining, interlining or contrast piece in the correct material marker and reconcile cut quantities. FIT’s Computerized Grading, Marking, and Specs course connects graded specifications and marker making directly to fabric properties.[2]
Evaluate a marker by both compliance and efficiency. Marker efficiency can be expressed as total pattern-piece area divided by marker length multiplied by usable width, then multiplied by 100. A high percentage is unacceptable if grain, shade, matching, quality zones or cut accuracy are compromised. Compare manual and automated nests, mixed-size ratios and alternative widths while keeping the production rules identical. Record marker ID, style and revision, size ratio, piece count, width, length, efficiency, fabric direction and approval. Lectra recommends measuring marker efficiency, fabric yield, re-cuts and first-pass quality, and basing estimation on actual constraints such as width, shrinkage, motifs and rotation rules.[9]
Practice
Create two compliant markers for the same four-size order using different size ratios or fabric widths. Calculate efficiency, reconcile every piece and quantity, and explain which marker should be released.
Checkpoint
All cutting constraints and quantities must be satisfied, efficiency calculations must use usable width, and the approved marker must improve consumption without changing grain, matching, quality or pattern revision.
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Fabric consumption calculations
Fabric consumption is the purchasable material length required for a garment or production order, not simply the visible area of its pattern pieces. For an early sample estimate, place the complete pattern set within the confirmed usable width and record the required length; area divided by width is only a theoretical minimum because real pieces cannot always nest without gaps. For production, calculate each lay separately: multiply marker length by the number of plies, then sum all lays and add documented allowances for ends, splices, shrinkage, relaxation, defects, shade separation, bow or skew, print or check matching and cutting loss. Divide total planned length by the number of complete garments produced by those lays to obtain average consumption per garment.
Keep the unit logic visible. If a 5.80 m marker contains complete pattern sets for four garments per ply and is spread for 20 plies, it consumes 116 m before allowances and produces 80 garments, or 1.45 m per garment. Apply shrinkage mathematically rather than adding an unexplained percentage: where 3% length shrinkage must be allowed, divide the required post-shrink length by 0.97. Recalculate when usable width, size ratio, pattern revision, matching rule or order quantity changes. Lectra’s production-estimation guidance uses width, shrinkage, motif repeat, rotation and size-mix constraints and compares estimate with actual yield and re-cut performance.[9][10] Track purchased, issued, cut, returned and wasted quantities so future allowances reflect evidence.
Practice
Calculate net and purchasing consumption for a multi-size order with two lays. Include marker lengths, size ratios, ply counts, usable width, 3% shrinkage and stated end or defect allowances, then compare planned and actual usage.
Checkpoint
The calculation must reproduce the ordered size quantities, units and allowances must be explicit, average consumption must reconcile with total length, and every variance between planned and actual use must have an identified cause.
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