Tamil Nadu HSE First Year Textile and Dress Designing cheat sheet

Fibre classification: natural (vegetable, animal, mineral) and man-made (regenerated, synthetic); vegetable fibres are cellulose, animal fibres are protein.

Cotton fibre is a single collapsed cell, convoluted ribbon, 10-65 mm long; moisture regain about 8.5 per cent; burns with paper smell and grey ash.

Silk is the only natural filament fibre, secreted by the silkworm larva; wool has overlapping scales giving felting shrinkage and warmth.

Jute is a bast (stem) fibre, lignified, used for sacking and carpet backing; flax gives linen, a strong cool cellulose fibre.

Synthetic fibres are formed by extrusion through spinnerets: wet, dry or melt spinning; polyester and nylon are melt spun, viscose is wet spun.

Essential fibre properties: length-to-breadth (fineness) ratio above 100 for spinnability, plus strength, elasticity, moisture absorption and cohesiveness.

Identification tests: burning test (odour, flame, ash), microscopic test (convolutions, scales), chemical solubility test, and staining test.

Terms: hygroscopic (absorbs moisture), thermoplastic (softens on heating, e.g. polyester), elastomeric (high extensibility, e.g. spandex).

Cotton yarn sequence: opening and cleaning, carding, drawing, combing (optional), roving, ring spinning, winding and doubling.

Carding individualises fibres and forms sliver; combing removes short fibres and neps, producing finer, smoother, stronger yarn.

Twist direction: S twist (spiral follows middle of S) and Z twist; ply yarn twist is usually opposite to the single yarn twist.

Yarn count systems: indirect (cotton count Ne = length in hanks of 840 yd per pound) and direct (tex = grams per 1000 m; denier = grams per 9000 m).

Conversion: tex = 590.5 / Ne (approximately); higher Ne means finer yarn, higher tex means coarser yarn.

Yarn types by structure: single, ply, cabled (folded), core-spun, fancy or novelty (slub, bouclé, nub) and filament yarns (flat, textured).

Twist multiplier controls yarn character: high twist gives crisp, hard yarns; low twist gives soft, bulky yarns.

Yarn defects: neps, slubs, thick and thin places, hairiness, and count variation; measured by evenness (Uster) testing.

Woven fabric = two sets of yarns at right angles: warp (lengthwise, stronger, more twisted) and weft (crosswise, less twisted).

Basic weaves: plain (warp and weft alternate, strongest, e.g. poplin, muslin), twill (diagonal lines, e.g. denim), satin (floats give lustre, e.g. satin).

Fancy weaves include dobby, jacquard, pile (terry, velvet), double cloth and leno; jacquard can produce large intricate designs.

Weaving operations: shedding, picking, beating-up, taking-up and letting-off; a selvedge is the self-edge of the woven fabric.

Knitting: weft knitting (single jersey, rib, purl, interlock) uses one yarn across the width; warp knitting uses many parallel yarns (tricot, raschel).

Knitted fabrics are stretchy, porous and ladder-prone; wales run lengthwise, courses run crosswise.

Non-woven: web of fibres bonded mechanically (needle punching), chemically (adhesive) or thermally, or by spun-bonding; used in interfacing, wipes, disposable items.

Other constructions: braiding, lace, net and felt (matted wool fibres, no yarn structure).

Finishing stages: preparatory (desizing, scouring, bleaching, mercerising), colouration (dyeing, printing) and functional finishing.

Mercerising is treatment of cotton with strong caustic soda under tension: increases lustre, strength and dye affinity, and improves dimensional stability.

Mechanical finishes: calendering (lustre, smoothness), sanforising (shrinkage control), raising, schreinerising, embossing and heat setting for synthetics.

Chemical finishes: crease-resist, water-repellent, flame-retardant, anti-static, softening, moth-proofing and easy-care finishes.

Dye classes: direct (cotton, simple), reactive (cotton, excellent fastness), vat (cotton, very fast), acid (wool and silk), disperse (polyester), basic (acrylic).

Dyeing methods: fibre, yarn, piece and garment dyeing; union dyeing gives solid shades on blends, cross-dyeing gives two-colour effects.

Printing methods: block, screen (flat and rotary), roller, transfer (sublimation on polyester) and digital inkjet printing.

Fastness properties assessed: washing, rubbing (crocking), light, perspiration and sublimation fastness, rated on grey scales.

Elements of art: line, shape, form, colour, texture, space and value; principles of design: balance, rhythm, proportion, emphasis, harmony and unity.

Colour dimensions: hue (name), value (lightness/darkness) and intensity (saturation or chroma).

Colour wheel: primary (red, yellow, blue), secondary (orange, green, violet), tertiary colours from mixing adjacent hues.

Colour schemes: monochromatic (one hue in tints and shades), analogous (neighbouring hues), complementary (opposite hues), split-complementary and triadic.

Warm colours (red, orange, yellow) appear advancing and enlarging; cool colours (blue, green, violet) appear receding and slimming.

Balance may be symmetrical (formal), asymmetrical (informal) or radial; rhythm is created by repetition, gradation, radiation and transition.

Proportion relates garment divisions to each other and to the body, often using the golden mean or three-to-five ratio.

Texture is the surface quality, visual or tactile; emphasis creates a focal point through contrast of colour, line or texture.

Figure types: ideal, stout (large bust/waist/hips), thin (slender), and irregular figures such as stoop, sway back, prominent abdomen, large hips and sloping shoulders.

Body measurements needed: bust, waist, hip, shoulder width, back neck to waist, front neck to waist, sleeve length, armhole, dart and crotch depth.

Stoop figure: longer front waist length, shorter back; needs a wider back shoulder and raised back neckline.

Prominent abdomen: shorten front bodice or add extra length at front waist; sway back needs a shortened centre back waist.

Garment components: bodice, yoke, collar, sleeve, cuff, placket, pocket, belt, facing, interfacing, lining and fasteners.

Sleeve types: set-in, raglan, kimono, puff, cap, bell and dolman; collars: Peter Pan (flat), shirt (convertible), shawl and sailor.

Plackets are finished openings for fasteners; facings finish raw edges and are cut to shape of the edge; interfacing stiffens and supports.

Darts convert flat fabric to three-dimensional shape; they are placed to follow body contours (bust, waist, shoulder, elbow).

Methods of pattern making: drafting (measurement method), draping (on dress form), flat pattern (adaptation of basic block) and commercial pattern use.

Drafting needs accurate measurements, a basic block (sloper) without seam allowance, and standard ease: about 5 cm bust, 2 cm waist, 5 cm hip for a bodice.

Seam allowance: 1 cm on most seams, 1.5-2 cm on curved or fitting seams, 4-5 cm on hems; cutting line includes allowance, stitching line does not.

Pattern markings: grain line (parallel to centre front/back), notches, fold line, dart, buttonhole, balance marks and perforations.

Grain line must follow warp (lengthwise) direction; off-grain cutting causes twisting, hanging and poor fit.

Bodice block steps: draw rectangle from bust and back length, mark armhole depth, neckline, shoulder slope, bust and waist darts, then true the seams.

Alterations: slash-and-spread to add fullness, pivot method to move darts, and slash-and-overlap to reduce fullness.

Pattern grading increases or decreases a pattern through sizes while keeping proportions; a muslin/toile test fit is checked before cutting fabric.

Measuring tools: tape measure, ruler, L-square, set square, French curve; marking tools: tailor's chalk, tracing wheel and carbon, pencil.

Cutting tools: shears (bent handle), pinking shears (zigzag, for finishing), seam ripper, rotary cutter; pressing tools: iron, sleeve board, pressing cloth.

Sewing machine parts: needle plate, feed dog, bobbin case, presser foot, tension discs, take-up lever, spool pin, hand wheel.

Machine needle size is chosen by fabric weight: fine needles (size 9-11) for light fabrics, heavier (14-16) for denim and canvas; ballpoint for knits.

Temporary stitches: basting (even and uneven), tacking, tailor's tacks; permanent hand stitches: running, back stitch, hemming (slip, blind), blanket and buttonhole stitch.

Stitch classes: straight stitch, zigzag, overlock, chain stitch and decorative stitches; stitch length 2-3 mm for ordinary seams.

Seams: plain (open or pressed to one side), French (enclosed, for sheer fabrics), flat fell (strong, for jeans), run-and-fell, lapped and welt seams.

Seam finishes: pinking, overcasting, overlocking, binding, French binding and Hong Kong finish; seam puckering is controlled by correct tension and stitch length.