Abstract: A dye composition of 99.7% pure glycerin and press cake dye is provided along with an apparatus and method of use for the same. The apparatus sets the dye composition into polyester yarns by heating the composition to 160-190.degree. C. and then cooling the composition to 100-140.degree. C. Prescour, dye scour and post scour vessels are provided to facilitate the dyeing process. The fluids used in the apparatus and process are recycled by recycling units.