How To Prepare Fabric

Why Pre-wash Fabric?

  • Preshrinking fabrics removes excess dyes and chemical finishes used in the manufacturing process.
  • Most cotton fabrics shrink 2-3% when washed and dried, so if they are not preshrunk, the fabric may pucker at the stitching lines the first time it is washed.
  • Some dark or vivid colours need to be checked for colourfastness to determine whether the dye bleeds to light coloured fabrics or colours the water. 

How To Pre-wash Fabric

  • Use a mild soap to machine wash fabric before you cut it for sewing. 
  • Do not use soap intended for fine woolens as it may yellow cotton fabrics. 
  • If the colour bleeds use a colour catcher in the wash, some people also recommend using household vinegar to prevent colour bleeding. 

How To Test for Colourfastness

  1. Fill a glass with warm water and a few drops of mild soap, such as dishwashing liquid. 
  2. Cut a small square of fabric and place in the water. Allow to soak until the water has cooled slightly. Swish fabric. 
  3. Place wet fabric on a sample of light-coloured fabric; blot dry. If dye transfers to the light coloured fabric, repeat the test; if fabric still bleeds, it is probably not colourfast.