In this study, dyeing of two regenerated polyester fibers, poly-trimethylene terephthalate (PTT) and poly-lactic acid (PLA), with natural dyes were compared with that of poly-ethylene terephthalate (PET) fiber. Lac was used as the primary natural colorant while Catechu was chosen as a natural color that can also act as a biomordant. The effects of temperature, initial pH of dye bath and dyeing ...