Tamil Nadu HSE Second Year Textile and Dress Designing cheat sheet

Fibre classification: natural fibres split into vegetable (cotton, jute, linen, coir), animal (wool, silk), and mineral (asbestos); man-made fibres split into regenerated (viscose, acetate) and synthetic (polyester, nylon, acrylic).

Cotton is about 90% cellulose; the fibre is a collapsed tube with natural convolution that gives grip for spinning. Maturity and staple length decide yarn quality, not just fineness.

Wool is a protein (keratin) with overlapping scales; scales cause felting and shrinkage under heat plus agitation. Silk is also protein (fibroin) but is a continuous filament, so it needs no combing.

Linear density: tex = mass in g per 1000 m; denier = mass in g per 9000 m. Conversion: 1 tex = 9 denier. Cotton count (Ne) is the number of 840-yard hanks per pound, so higher Ne means finer yarn.

Twist direction: S-twist runs like the middle stroke of S, Z-twist like the middle of Z. Singles yarns are usually Z-twisted and plied yarns S-twisted to balance torque.

Twist multiplier (TM) = turns per inch divided by the square root of the cotton count. Higher TM gives a harder, stronger, less lustrous yarn used for warp; lower TM gives softer weft and knitting yarn.

Staple yarns are made by carding or combing then drawing, roving and spinning; combing removes short fibres and aligns the rest, giving a smoother, stronger, more expensive yarn.

Yarn irregularity (CV%) measures thickness variation along the length; it rises with shorter fibres, poor drafting and uneven blending, and shows up later as fabric barré and shade bands.

Three basic weaves: plain (over one, under one - strongest interlacing, e.g. poplin, cambric), twill (floats of two or more, visible diagonal, e.g. denim), and satin/sateen (floats of four or more, lustrous face, poor abrasion resistance).

Loom motions: primary (shedding, picking, beat-up) and secondary (let-off, take-up). Warp is the lengthwise set of ends; weft is the widthwise picks. Ends per inch (EPI) and picks per inch (PPI) set fabric cover.

Fabric weight in g/m² = (EPI × warp count factor) + (PPI × weft count factor) computed from yarn linear density; gsm rises with coarser counts, higher sett and thicker yarn.

Derivatives of plain weave include rib (warp or weft), basket/hopsack (two or more yarns acting as one), and mock leno. Twill derivatives include herringbone, diaper and steep/gentle twills.

Knitted structures: single jersey has face loops on one side and purl on the other and curls at the edges; rib 1×1 alternates wales and is elastic; interlock is two 1×1 ribs interlocked and does not curl.

Non-wovens are bonded by needle punching, thermal bonding or chemical/adhesive bonding; they have no yarn interlacement, so strength is lower but production speed is far higher.

Selvedge is the self-edge formed where weft turns; a firm selvedge prevents curling and fraying. Fabric width is measured between selvedges and is narrower after wet finishing due to relaxation shrinkage.

Warp preparation sequence: winding, warping, sizing (to add abrasion resistance), then drawing-in and denting before weaving. Sizing adds weight and strength but must be removed in desizing.

Finishing sequence: singeing, desizing, scouring, bleaching, mercerising (cotton), then dyeing or printing, then mechanical/chemical finishing. Mercerising uses strong caustic soda under tension to add lustre, strength and dye affinity.

Dye–fibre pairing rule: reactive and vat dyes for cellulose; acid and chrome dyes for wool and silk; disperse dyes for polyester and other synthetics; basic (cationic) dyes for acrylic. Wrong pairing gives poor fastness.

Dye fastness is reported on a 1–5 grey scale (5 = no change/staining). Wash fastness, light fastness, rubbing (crocking) fastness and perspiration fastness are tested separately.

Printing methods: block (hand, repeat marks possible), screen (flat or rotary, most common for bulk), roller, transfer (sublimation for polyester) and digital inkjet (low minimum order, unlimited colours).

Mechanical finishes: calendering (glaze and flatten), sanforising (compressive shrinkage control on cotton), raising (brushing a nap), schreiner calendering (lustre). Chemical finishes: easy-care/resin, water repellent, flame retardant, anti-microbial.

Shrinkage control: sanforising holds cotton below about 1% residual shrinkage; wool is shrink-resisted by chlorine/Hercosett polymer treatment to stop scale felting.

Colour measurement uses the CIELAB Lab* system; L* is lightness, a* red-green, b* yellow-blue. Delta E quantifies the total colour difference between a sample and a standard.

Effluent from dyeing carries high BOD, COD, colour and salt load; treatment uses primary settling, biological oxidation and colour removal before discharge, and reverse osmosis enables water reuse.

Body measurements needed for a bodice: bust (fullest point), waist, hip, shoulder width, back neck to waist, front neck to waist, armhole depth and sleeve length. Take measurements over light clothing with the tape snug, not tight.

Drafting order for a bodice block: establish the centre-back line, mark the nape-to-waist length, square out for bust, waist and hip lines, then build the neckline, shoulder slope, armhole and side seam.

Dart manipulation moves a dart without changing the fit: pivot the pattern around the dart point to relocate fullness to the shoulder, neckline, armhole, waist or centre front; slash-and-spread achieves the same by cutting.

Seam allowance: 1 cm on curved and normal seams, 1.5–2.5 cm on straight edges and hems; add extra at the centre-back for a placket. Grain line must run parallel to the centre front or back.

Common seams: plain (open or pressed to one side), French (self-neatening, for light fabrics), flat fell (for denim and shirts), run-and-fell, and overlock. Bias binding finishes curves and necklines.

Zip insertion types: centred, lapped and invisible. An invisible zip is set into a seam with a concealed foot; a lapped zip is used on trousers and skirts with a fly or side opening.

Pattern grading changes a base size to other sizes by adding or subtracting fixed increments at specified points; it is not the same as altering for an individual figure.

Muslin/toile fitting checks balance, ease, dart position and grain; correct the pattern, not just the calico, and transfer every correction back to the paper pattern.

Fashion figure proportions are stylised: about 8.5 to 9 heads tall for croquis, with the waist above the midpoint and legs roughly half the total height; the real figure is about 7.5 heads.

Elements of design: line, shape/form, colour, texture, space. Principles: balance, rhythm, emphasis, proportion, harmony and unity. Every design analysis should name both elements and principles used.

Colour wheel relations: monochromatic (one hue), analogous (neighbours), complementary (opposite), split-complementary and triadic. Value is lightness, intensity/saturation is purity of the hue.

Colour and figure: warm, light and bright colours advance and enlarge; dark, cool and dull colours recede and slim. Vertical lines lengthen; horizontal lines widen; diagonal lines give movement.

Illustration media: pencil for croquis, fine liner for technical flats, watercolour and marker for rendering, and gouache for opaque flat colour. Technical flats are drawn to scale with no figure.

Fashion cycle stages: introduction, rise (peak), decline and obsolescence. Classic styles stay within the cycle for years; fads complete the cycle in one or two seasons.

Design development documents the process: inspiration board, mood board, colour card, fabric swatches, croquis sketches, working drawings and a final illustration with specification sheet.

Silhouettes named for shape: A-line, empire (seam under the bust), princess (vertical shaping seams), shift, tent, sheath, peplum and yoke. Name the silhouette when describing a garment.

Care label symbols: a washtub with a number is the maximum wash temperature in °C; a tub with a hand means hand wash only; a triangle means bleach (crossed out = do not bleach); a square with a circle is tumble drying; an iron shows dot settings (1 dot ≈ 110 °C, 2 ≈ 150 °C, 3 ≈ 200 °C).

Fibre care rules: cotton tolerates hot wash and strong detergent; wool needs cool water, neutral detergent and flat drying; silk needs mild soap, no wringing and drying in shade; viscose loses strength when wet, so handle gently.

Polyester, nylon and acrylic are thermoplastic: iron at low temperature, never press acrylic directly, and keep heat away to avoid glazing and shrinkage.

Stain removal order: remove excess, test on a hidden seam, work from the back of the stain outward, use cold water for protein stains (blood, egg, milk) because heat sets them, and blot rather than rub.

Bleach types: sodium hypochlorite (chlorine) attacks wool, silk and many synthetics; hydrogen peroxide and sodium perborate are oxygen bleaches and safer for coloured and protein fabrics.

Storage: hang tailored garments on shaped hangers, fold knits flat to avoid stretching, store wool with neem or cedar to deter moths, and air clothes before storing to remove moisture.

Laundry aids: detergent removes soil by wetting and emulsifying; starch adds body; blue whitener masks yellowing; fabric softener (cationic) reduces static and stiffness but lowers absorbency of towels.

Business plan essentials: product and market, target customer, competitor analysis, production plan, costing and pricing, marketing plan, finance and break-even, and risk.

Costing formula: total cost = material + labour + overheads; selling price = total cost + desired profit margin. Gross margin = (selling price − direct cost) ÷ selling price × 100.

Break-even quantity = fixed cost ÷ (selling price per unit − variable cost per unit). This tells the minimum number of garments to sell before profit begins.

Registration route in Tamil Nadu: MSME/Udyam registration, GST registration above the turnover threshold, current account, and Coir Board/Handloom or Textile Ministry schemes for subsidies and exhibitions.

Career paths: garment technician, pattern maker, CAD designer (Gerber, Lectra, Optitex), quality controller, merchandiser, textile chemist, dye-house supervisor, fashion entrepreneur and textile teacher.

Institutional support: NIFT, Anna University textile technology departments, SITRA (South India Textile Research Association, Coimbatore), NITRA and the Handloom Design Centres offer testing, training and design help.

Export documentation: buyer purchase order, proforma invoice, commercial invoice, packing list, shipping bill, bill of lading and certificate of origin. AQL 2.5 (acceptable quality limit) is a common inspection level for garment export.

Digital marketing for a small label: catalogue with flat sketches, size chart, fabric and care details, consistent photography, and pricing that already includes platform fees and shipping.

Record structure: aim, materials and tools, procedure, observation, diagram or sample, and conclusion for every practical. Date each entry and keep the index page updated.

Fibre identification practicals: burning test (cotton burns like paper with grey ash, wool smells of burnt hair and leaves a crushable bead, polyester melts and beads hard), plus microscopic and chemical solubility tests.

Yarn practicals: measure count by cutting a known length, weighing it, and applying the count formula; measure twist with a twist tester and record turns per inch or per metre.

Fabric practicals: thread count by counting ends and picks per inch with a pick glass; weave identification by raveling and sketching the interlacing; weight by cutting a 10 cm × 10 cm square and weighing it.

Dyeing and finishing practicals: record dye class, recipe (dye %, salt, alkali, temperature, time, liquor ratio) and the fastness result on the grey scale; keep a dyed swatch with the entry.

Pattern practicals: submit the drafted block with measurements, the true-to-size muslin, and the corrected final pattern; label grain line, darts, notches and seam allowance.

Garment construction practicals: attach a sample of each seam, dart, placket, collar, pocket and fastening on a stitched sample sheet rather than describing them only in words.

Internal assessment marks usually combine record neatness and completeness, practical skill test, viva voce and project work; a portfolio or swatch book with numbered samples strengthens the submission.