Jacquard Blue iDye Poly is for synthetic fibres such as polyester and nylon. It even works on some plastics—buttons, frisbee discs, 3D printed objects, dolls and more! The dye comes in a dissolvable packet, so there are never any messy powders to handle: simply drop the packet in a pot of water, add your fabric and bring to a boil! iDye Poly may also be used for sublimation printing techniques and to dye the polyester threads that are used to sew commercially manufactured garments.