No, you can use the iDye Poly with other types of dyes, but you must adhere to the Poly temperature. You can mix Procion, Acid Dye, or iDye Natural in the same pot for a mix blend garment and dye all threads simultaneously. The poly does not react with the other dyes, so it will dye the poly portion and the natural dye will dye the natural portion. Soda Ash and vinegar do not affect iDye Poly’s performance. You can choose the same color for poly and natural, or you can choose similar or disparate colors of your choice. iDye Poly will dye the poly portions and the natural dye will dye the natural portions.