ITI/NCVT Sewing Technology (AITT Theory) key terms

The direction of the warp yarns running lengthwise through a woven fabric. Pattern pieces are marked with this line so they are placed on the fabric in the correct orientation.

The tightly woven, self-finished edge running along both lengthwise sides of a woven fabric. It prevents fraying and marks the lengthwise grain direction.

A diagonal direction across a woven fabric at 45 degrees to the warp and weft yarns. Bias-cut fabric stretches easily, so it is used for draping and bias binding.

The set of parallel lengthwise yarns held under tension on the loom during weaving. Warp yarns are usually stronger and more tightly twisted than weft yarns.

The yarn inserted crosswise over and under the warp yarns during weaving. It forms the width of the fabric and is also called the filling or pick.

The simplest woven structure, in which each weft yarn passes alternately over and under each warp yarn. It produces a firm, strong, flat fabric such as poplin or calico.

A woven structure producing diagonal lines on the fabric surface because weft yarns float over two or more warp yarns in a stepped pattern. Denim and gabardine are twill fabrics.

The flat metal plate beneath the presser foot that supports the fabric during stitching. It has a hole for the needle and feed dog slots, and its markings guide seam allowance.

The toothed metal part below the needle plate that rises through its slots and moves the fabric forward by a set stitch length with each stitch cycle.

The hinged metal foot that holds the fabric firmly against the feed dog while stitching. Its pressure must be adjusted to suit light or heavy fabrics.

The distance the fabric advances between two consecutive needle penetrations, usually expressed in millimetres. It is set on the machine and affects seam strength and appearance.

The number of stitches per unit length of seam, commonly measured per centimetre or per inch. Correct density gives strong seams without puckering or thread breakage.

The narrow strip of fabric between the raw edge and the stitching line, usually 1 to 1.5 cm in garments. It allows the seam to be joined and finished without fraying.

The line of stitching that joins two or more pieces of fabric edge to edge. Its type and finish determine the strength, bulk and appearance of the garment.

The most common seam, made by placing two fabric pieces right sides together and stitching a straight line parallel to the raw edges. The allowances are then pressed open or finished.

A strong seam enclosing all raw edges, made by stitching a narrow seam wrong sides together, trimming it, then turning and stitching again to enclose the first line. Used on sheer and light fabrics.

A stitch formed by one or more needles and loopers that joins and simultaneously edges fabric, preventing fraying. It is produced on an overlock or serger machine.

A few reverse stitches made at the beginning and end of a seam to lock the thread and prevent it from unravelling. Most industrial machines perform it with a reverse lever or button.

A finished opening in a garment that allows it to be put on and taken off easily, usually containing buttons or a zip. It is often reinforced with a facing or strip of fabric.

A piece of fabric sewn to the inside edge of a garment opening and turned to the wrong side to finish it neatly. It is cut to the same shape as the edge it finishes.

A layer of fabric attached to the wrong side of a garment part to give it body, shape or firmness. It is used in collars, cuffs, plackets and waistbands.

An interlining coated with heat-activated adhesive that bonds to fabric when pressed with heat and pressure. It stiffens collars, cuffs and plackets quickly but needs correct temperature control.

The garment component attached around the neck opening, available in styles such as shirt, stand, Peter Pan and shawl. It is usually cut in pairs and interlined for shape.

The garment part that covers the arm, attached at the armhole. Common types include set-in, raglan, kimono and puff sleeves, each with a different construction method.

A small bag or patch attached to or set into a garment for carrying items. Types include patch, welt, bound and in-seam pockets, each with distinct construction steps.

The process of drawing full-size garment pattern pieces on paper from body measurements using drafting rules. The resulting patterns are used to cut fabric accurately.

The extra allowance added to body measurements when drafting a pattern so the garment fits comfortably and allows movement. It is added on top of the actual body size.

The process of laying out fabric in smooth, even layers of the required length on the cutting table before cutting. Correct spreading keeps grain and ply alignment accurate.

A plan drawn to scale showing how pattern pieces are arranged on the fabric to minimise waste. Efficient markers reduce fabric consumption and production cost.

The operation of separating fabric plies into garment parts using a cutting machine or hand shears, following the marker. Accuracy here affects fit, symmetry and fabric waste.

The percentage of total fabric consumed that actually becomes garment parts, rather than waste. Higher utilisation lowers material cost per garment.

A document listing all cost elements of a garment, such as fabric, trims, labour, overheads and profit, to calculate the selling price. It supports quoting and cost control.

The systematic analysis of work methods and time to improve efficiency and set fair production standards. It includes method study and work measurement on the shop floor.

The time, in minutes, allowed for a trained operator to complete a defined task at a normal pace, including allowances. It is used to plan capacity and calculate labour cost.

The allocation of work elements among operators on a production line so that each station has a similar workload and no bottleneck slows the flow.

Producing a small number of trial garments to confirm fit, construction and workmanship before bulk production. Approved samples serve as the reference standard for the order.

Acceptable Quality Level, the maximum percentage of defective units considered acceptable in a sampling inspection lot. It is used in inspection plans to decide acceptance or rejection.

A fabric inspection method that assigns 1 to 4 penalty points to defects according to their length or size, then compares the total with a set acceptance limit per unit area.

Sorting quality faults into critical, major and minor categories according to their effect on safety, function and appearance. Classification guides inspection decisions and corrective action.

The systematic checking of materials, components or finished garments against specified standards. It may be done at fabric, in-process, final or pre-shipment stages.

The application of heat, moisture and pressure with an iron or press to shape and smooth garment parts during construction and finishing. Correct pressing sets seams and improves appearance.

The final operations on a garment after assembly, such as trimming threads, stain removal, pressing and attaching labels. It prepares the garment for inspection and packing.

Wrapping and boxing finished garments with labels, size stickers and protective materials so they reach the buyer undamaged and correctly identified.

A sewing machine that forms a stitch by interlocking an upper needle thread with a lower bobbin thread. It is the most widely used machine in garment assembly.

The number indicating the thickness of a sewing machine needle, chosen to match fabric weight and thread. Too fine a needle causes skipped stitches; too heavy a needle damages fabric.

Items such as goggles, gloves, masks and ear plugs worn by workers to reduce exposure to workplace hazards. It is the last line of defence after engineering controls.

Physical covers, shields and interlocks fitted to machines to prevent hands and clothing from contacting moving parts such as belts, pulleys and needles.

The design of workstations, chairs and tasks to fit the human body, reducing fatigue and strain injuries. Correct table height and posture are essential in sewing rooms.

A workplace organisation method using sort, set in order, shine, standardise and sustain to keep the sewing floor clean, safe and efficient.