Fibres, Fabrics and Fabric Selection
This domain tests fibre identification, fabric terms and the reasoned choice of cloth for a purpose. Expect questions asking you to name a fibre from its properties, to identify a burn test result, or to justify a fabric choice.
Natural and man-made fibres
- Cotton - absorbent, cool, stronger wet than dry, shrinks, creases; burns with a paper smell and leaves grey ash.
- Silk - lustrous and strong but delicate when wet; burns with a hair smell.
- Wool - warm, elastic, felts on washing; burns with a hair smell, leaving a crushable bead.
- Jute - strong, cheap and coarse, and Bengal's own fibre; linen - cool and strong but creases badly.
- Rayon (viscose), polyester, nylon and acrylic are man-made; they are thermoplastic, so they melt and form a hard bead rather than ash.
Fabric structure terms
- Warp runs lengthwise and is stronger; weft runs crosswise; selvedge is the finished edge.
- Grain, true bias at 45 degrees (the most stretchy direction), thread count and GSM.
Choosing a fabric
Judge by purpose, comfort, durability, drape, shrinkage, colourfastness, cost and ease of care - not by appearance alone.
Worked example
A school shirt for a hot, humid district. Plain cotton poplin is chosen because it absorbs sweat, can be boiled and ironed hot, and is colourfast when well dyed. The trade-off is that it creases and shrinks, so it is preshrunk before cutting. A 65/35 polyester-cotton blend dries faster and creases less, but absorbs less - acceptable only if the child irons the shirt daily and the climate is less humid.
Traps that cost marks
- Classifying rayon or viscose as a natural fibre because it comes from wood pulp.
- Confusing warp with weft.
- Ignoring shrinkage allowance in cotton.
- Choosing a fabric by print without checking its weight for the garment.