The term 'soften fibers' can be summarized by the three letter acronym RET, which stands for 'relax, extend, and twist'. This is a technique used in the textile industry to soften fibers such as wool, cotton, and linen. The process involves relaxing the fibers, extending them to their full length, and then twisting them together to create a softer fabric. This technique is often used to create fabrics with a softer feel and more luxurious look.