The following is a general fabric care guide. Always prewash all fabric before use to avoid shrinkage on a completed sewing project. Our tip is to use salt to prewash them. Cottons and linens are machine washable in cold water (30° or lower) preferably using non-biological washing liquid. Screen printed fabrics should be washed by hand. Polyester fabrics are machine washable but do not iron directly. Drying fabrics in a tumble drier is not recommended. All fabrics should be ironed on a low-temperature setting.