Black iron oxide is a very strong black colorant for soaps. Start with a little iron oxide and work your way up. If too much is used it can bleed and stain washcloths. Before use in soap, black iron oxide should be blended in oil and then added to the soap. This helps disperse the oxide. Before adding to melt and pour, black oxide should be added to glycerin and then added to the soap.
Always test your products before sale to ensure that no staining or any other unwanted effects occur.
Safe for eyes, lips, and external use.
Recommended use rate in cold and hot process soap is .5 tsp. per pound of oils. For melt and pour, the recommended use rate is .25 tsp. per pound of base.