However, several new types of dyes had to be developed for more - modern synthetic materials such as acetate rayon, polyester, nylon, and acrylic fiber. Challenge to Color Fastness
पण अॅसिटेट रेयॉन, पॉलिएस्टर, नायलॉन आणि अॅक्रिलिक या इतर कृत्रिम व अत्याधुनिक धाग्यांकरता अनेक नवीन प्रकारची रंजकद्रव्ये तयार करावी लागली.