Fabric processing covers the preparation, coloring and finishing carried out on cloth before garment cutting. The treatments influence how the material feels, how much it changes during laundering and the dimensions supplied to the garment factory. Cotton sweatshirt fabric, for example, can receive mechanical raising to develop its brushed surface and compaction to reduce its remaining lengthwise shrinkage.

Fabric specifications also affect how a style moves from development into a production order. A low MOQ clothing manufacturer can work with smaller fabric quantities during an initial run, making finished GSM, usable width, shrinkage and color standards important before cutting begins. The same processing details are visible in finished streetwear clothing, where fabric weight, wash and surface texture directly shape the final appearance and hand feel.

Preparing Cotton at the Dyehouse

Woven cotton may arrive carrying size on its warp yarns. This coating protects the yarns during weaving. Where starch size has been used, an amylase treatment breaks it down so it can be removed during washing. The dyehouse selects the desizing treatment according to the material applied by the weaving mill.

After desizing, the cloth continues through preparation according to its required color and finish. Scouring removes natural impurities from cotton and improves absorbency. Alkali assists their release, a surfactant helps the liquid penetrate the material, and a sequestering agent binds metals present in the fabric or water. Washing carries the released matter out of the cloth. For white goods and pale shades, hydrogen peroxide bleaching develops the required white base. Its activity is controlled through bath pH, stabilizer, temperature and treatment time.

A mercerized finish adds a concentrated caustic-soda treatment. The cotton fibers swell and become more receptive to dye; holding the material under tension during treatment develops greater luster. Before dyeing, rinsing and neutralization remove residual preparation chemistry. Fabric that has been bleached also receives treatment to remove the remaining peroxide.

Choosing the Lab Dip

Place the lab dip beside its physical color standard in a light booth. Both pieces need even illumination and a consistent orientation, especially on fabrics with a directional surface. The color brief identifies the light sources used for assessment, including the primary illuminant and any additional retail or domestic lighting conditions relevant to the product.

The visual assessment and instrumental readings feed into the dyer’s next decision. A spectrophotometer measures the sample against the color standard. Where another adjustment is required, the dyer changes the formula and produces a further dip. The reference remains the same throughout these rounds, allowing successive recipes to be evaluated against one target.

Each new dip goes through the preparation needed for meaningful measurement. In reactive dyeing on cotton, this includes fixation followed by washing to remove unfixed dye and residual processing chemicals. The fabric is rinsed, dried and conditioned at the specified temperature and humidity before its color is measured. The resulting swatch returns to the light booth alongside the standard.

A match also needs to hold across the illuminants named in the brief. Different colorant combinations can reflect light differently, producing a change in the apparent relationship between the sample and reference as the illumination changes. This assessment gives the dyer information about the combination of dyes used in the formula.

The Repeat Printed on the Cloth

A rotary screen carries the artwork around a cylinder, so the design must join at the repeat boundary. The available screen repeat constrains the artwork’s lengthwise layout. Some rotary printing systems offer repeat sizes such as 640, 725, 819, 914 and 1,018 mm. The printer establishes the available repeat before screen preparation.

The artwork also has a specified size on the finished fabric. Identifying two corresponding points in successive motifs gives the printer a repeat measurement that can be checked throughout development. The specification can separately identify the width of a motif where its proportions are important to the design.

A reactive print continues through processing after the image has been applied. Drying holds the pattern in place before fixation. During steaming, the dye moves into the fiber and fixes; subsequent washing removes thickener, unfixed dye and remaining print-paste chemistry. The cloth then receives the drying and finishing treatments selected for production.

The finished trial provides the dimensions used to assess the delivered pattern. Measuring a span containing several complete repeats gives an average repeat length when that span is divided by the number of repeats. A separate measurement across the cloth establishes the transverse dimension. For artwork containing a circular motif, its two diameters provide a direct check on whether its proportions have changed.

Inside a Brushed Sweatshirt Fabric

On the technical back of three-thread fleece, the bulky backing yarn floats across the knitted structure. A binding yarn connects it to the face structure, where the ground yarn forms the smooth outer surface. The backing yarn supplies the fibers that will be raised during brushing. Its position and consistency are established during knitting, before the fabric reaches the finishing line.

The raising machine brings this back surface into contact with wire-covered rollers. Their points catch and lift fibers from the yarns. The arrangement of the wires and the relative movement of the rollers influence the raising action across the cloth. Where the finish includes shearing, the raised fabric passes a cutting assembly that trims projecting fibers to an even height. A rotating cutter works against a fixed blade as the material travels through the machine.

Curing at Fabric Temperature

Infrared sensors mounted inside a stenter can follow the temperature of the moving cloth. Readings taken at several positions identify where it reaches the temperature selected for a curing treatment. Combining those positions with the fabric’s travel speed establishes the time spent at that temperature.

For cotton shirting receiving a pre-cure easy-care finish, the cloth enters the drying and curing stage after resin, catalyst and softener have been applied. In a padding system, the fabric passes through the treatment bath and then between squeeze rolls that regulate liquid pickup. Water evaporates during drying, and the subsequent thermal treatment allows the resin reaction to take place before garment cutting.

Incoming moisture and fabric weight influence the point at which the cloth reaches its target temperature. A change in either can alter the available holding time inside the heated section. The operator can use the measured temperature profile to regulate line speed and maintain the exposure required by the selected finish. The curing recipe specifies fabric temperature and holding time alongside the machine settings.

Finished Width and Fabric Yield

For an open-width fabric with uniform weight across its width, the relationship between GSM and linear yield is:

Linear meters per kilogram = 1,000 � (GSM � full fabric width in meters)

GSM expresses mass per square meter. Multiplying it by the full width gives grams per linear meter; dividing 1,000 grams by that figure gives the calculated length per kilogram. The equation assumes the weight and width describe the same finished material under consistent moisture conditions.

Full width is used in this mass calculation because the purchased roll includes its edges. Usable width is a separate input for the cutting layout. Where a roll has unusable edge areas, their mass remains part of the purchase even though those areas are excluded from the garment pieces.

The mill can change these dimensions during finishing. A stenter grips the fabric edges on pins or clips, and the rail spacing controls its working width. Overfeed introduces cloth faster than the transport chain carries it forward, allowing lengthwise relaxation during the heated passage.

Compaction subsequently shortens the structure mechanically where that treatment is specified. Knitted loops elongated by processing tension can move into a more compact configuration. The delivered length decreases, and the fabric’s weight per unit area can rise as its area contracts. This treatment reduces the lengthwise shrinkage available during later laundering.

The purchasing calculation uses the resulting finished GSM and width. For the same uniform-fabric assumption, a kilogram price converts to a nominal linear-meter price as follows:

Price per linear meter = price per kilogram � GSM � full width in meters � 1,000

Garment consumption is then calculated from the cutting layout at the measured usable width, including the allowances selected for that order.

The Fabric Release Record

A release sheet can bring together the finished fabric code, color reference, production lot and roll identifiers. Enter the measured GSM with its permitted tolerance, then record full width, usable width and delivered length in separate fields. A retained swatch carrying the same identifiers provides a physical reference for the material supplied to the cutting room.

The laboratory results describe the fabric under specified test conditions. For dimensional change, AATCC TM135 measures the lengthwise and widthwise changes produced by the selected home-laundering procedure. Skew change is assessed under AATCC TM179. The washing and drying conditions accompany the results.

A functional finish introduces the corresponding performance requirement. For water-repellent fabric, AATCC TM22 assesses resistance to surface wetting through a spray test. A hydrostatic-pressure requirement uses a method such as AATCC TM127. The product specification identifies the required result and the condition of the material being tested, including any laundering treatment completed beforehand.