Fabric Grain – A Detailed Explanation.
You may already know about fabric grain, or perhaps you may not! I have encountered students on the second year of their degree in fashion, who did not know about the grain of fabric!
Hopefully those of you that know a little may still learn something here!
Grain refers to placement of threads in a woven fabric, knowledge and understanding of fabric grain is really important when designing, drafting patterns and making any garment.
WARP-WEFT-BIAS
The WARP threads run parallel to the selvedge (the finished edge of your fabric), the WEFT threads run at right angles to the warp, i.e. from selvedge to selvedge (the cut edge). The WARP thread is the stronger of the two.
The WEFT threads should run around the garment, i.e. horizontally, this provides greater elasticity in wear.
The BIAS grain runs at 45 degrees to the warp and weft and provides the greatest amount of natural stretch. The BIAS grain is ideal for draped or softly moulded garments, as garments cut on the bias are more fluid and mould to the body closely.
When making a full circle skirt some sections will unavoidably be cut on the bias, this will result in these sections dropping more at the hem line, therefore it is essential to hang bias cut garments for at least 24 hours and revisit the hem line to make alterations.
If you take a look at my post on circular skirts, you will see how you can achieve different looks by cutting the skirt in different ways!
Grain is important as it effects the whole balance of the garment, garment sections cut off grain will twist on the body, you may well have noticed a pair of trousers you have that twist around the leg, this will be because the trouser pattern section has been cut off grain, this is often seen in cheaper garments as cutting off grain allows the manufacturer to fit more pattern sections on the fabric and save money!
Grain strongly influences how pattern sections are placed on the fabric, therefore garment pattern sections should be placed with the WARP threads running parallel to the center front (CF) and center back (CB) etc. This means that the WARP threads run vertically through the garment.
Unfortunately once a garment has been cut off grain there is no possibility of redemption, the signs of a garment having been cut off grain are listed below and should be taken into consideration when you are assessing the fit of a garment.
The material in the leg of a trouser appears to twist slightly to the left or the right and does not lie correctly on the inside leg, unfortunately this may not be spotted until the garment has been washed and dried.
A skirt that is intended to have an even hem line has dropped in one area of the hem.
One side of a neckline appears not to lie flat against the body, or appears to behave differently to the other side of the neckline, for example a cowl neck may hang heavier on one side than the other.
Badly cut garments that have incorrect grain that are produced in a patterned or check fabric can distort the appearance of the fabric.
All of the above are common faults found in cheaper garments, where the manufacturer has tried to save money by tilting the pattern pieces, when cutting the garment out.
Grain Lines on Basic Blocks
Strictly speaking a basic block should have a grain line with no arrows at the ends. Arrows on both ends of a grain line indicate that the pattern piece can be cut facing in either direction, arrows just on one end indicate that the pattern pieces should all be cut facing one way. Fabrics with a nap or pile such as velvet need to be cut in one direction only. Fabrics with a nap should be cut with the ‘pile’ lying as your hair would grow – downwards.
Grain lines, if cutting on the straight of grain, are always parallel to the CF or CB. Grain lines on trousers and sleeves run down the center line. A grain line on the center of a trouser is also referred to as a crease line.
Pattern sections to be cut on the bias grain have grain lines marked at 45 degrees to the straight grain.
Also take note that –
When pattern sections are traced from a master pattern, measure carefully from the original grain lines to place new grain lines on any traced sections, where the original grain line may not be present.
Hopefully you now have all the information you will need on grain and grain lines!
Happy pattern drafting!
Nicola
