From McCall’s sewing in Colour.
When placing a pattern piece on to the fabric in preparation for cutting it is obviously incredibly important to make sure it is cut out in the correct Grain. Straight Grain isn’t stretchy, & Cross Grain or Bias Cut is. This means that unless the pattern has been designed to be cut on the Bias, it is important to make sure it is cut on the Straight Grain or the final garment can twist & stretch on the form.
Place the paper Pattern piece onto the fabric. Pin through all layers at one end of the Grain Line mark- an extended arrow. Using a Tape Measure as illustrated above, measure from the pin to the selvedge or folded edge of the fabric. Make a note of the measurement & move the Tape Measure along to measure from the selvedge across to the other end of the Grain Line mark. Move the paper Pattern piece until the mark measures exactly the distance the other end does & pin in place.
Continue to pin around the paper Pattern, & move to the next piece measuring the Grain Line where necessary.