Unless you won't be washing your finished project, new fabrics should be prewashed and dried in the same way the finished project will be washed and dried. We'll walk you through why and how to prewash your fabrics.
Shrinkage - Fabrics made from natural fibers can shrink up to 5-10%. When making a garment or other item that has to fit correctly, prewashing can prevent unwanted shrinkage after the item is completed. Prewashing is especially important if you are using more than one fabric in your project, as they may shrink at different rates.
Cleaning - Prewashing your fabrics will remove any remaining spinning oils and soften your fabric, and will help to remove any excess color (especially important for naturally dyed fabrics).
Step 1 - Finish Edges: Woven fabrics sometimes fray when washed and dried. This can be prevented pinking or stitching the cut edges. Cut edges of knit fabrics do not have to be finished because the don't fray.
Step 2 - Wash and Dry: Unless you plan to always wash your finished item in cold water and dry on a line, fabrics should be prewashed with like colors, using the hottest water that you might use when washing the finished item, and tumbled dry. A special note for naturally dyed fabrics - make sure that the rinse water for naturally dyed fabrics is clear, and these fabrics may require more than one prewash.
Step 3 - Press: Before cutting out your project, press the fabric on the hottest setting appropriate for the fiber.
Conclusion: Taking the time to prewash and dry your fabrics will help you to achieve the best results in your sewing. For more tips on washing and drying fabrics of different fiber content, watch for our next post.