Stress-relaxation experiments on four varieties of Indian Silk fiber show that stress relaxation is significantly greater in non-Mulberry silks than in the Mulberry silk and that the differences among non-Mulberry silk fibers are relatively small. All the fibers studied also exhibit inverse stress relaxation. It has been shown that the Maxwell-Wiechert model, with two Maxwell elements in parallel, can be used to analyze and explain both the stress-relaxation and inverse stress-relaxation behaviors.