Shipped in a resealable bag that is sealed for safety and freshness. It includes a tear-off tab for easy opening. Ideal for making magnetic putty/slime. Gloves are recommended when using it since it is a very fine pigment . Fe3O4, also known as magnetite or Iron (II,III) Oxide This comes from a synthetic source and is produced by Rockwood Particle size runs about 0.30 micron Used in welding, fertilizers, pigments, ceramics, along with a lot of other uses We sell bulk for so many different uses, we don’t include any specific use instructions