Both ends can be used to transfer pattern markings lor needlecraft, quilting, crafting and sewing. Blue ink removes with damp cloth. Purple disappearing ink can be left to fade away or can be removed with water. Use the purple disappearing ink on projects to be completed within 24 hours. This ink normally disappears in 48-72 hours or it can also be removed by gently rubbing with a clean damp cloth. The blue wash out pen is best used on washable fabric. To remove the blue markings, rub gently with clean damp cloth well moistened with plain water.