We recommend prewashing washable fabrics before sewing. This helps eliminate shrinkage before you make your project. Always wash gentle and dry cold or warm, not hot. Be sure to unfold the fabric before washing. When possible, hang/lay flat to dry (Hot dryers wear, shrink, and wrinkle fabrics). Re-inspect fabric after washing. Do not use bleach or detergent with bleach additive. Wash dark cottons and rayons separately, using a mild soap. Dark prints may require extra rinsings to remove excess dye.
Fabric care varies, be sure to check the details and recommendations for each fabric before starting your project.