Cleaned cocoons were degummed by boiling with 5 g/L of Na2CO3 solution for 3 h. Boiled cocoons were soaked in StarSoft solution of 50 mL/L of distilled water for 3 minutes and washed twice with hot and cold distilled water. The degumming process was repeated for all except B. mori and G. postica cocoons. Degummed fibers were soaked in 70% ethanol for three days to remove remnant sericin and fatty materials and then dried at room temperature. Fiber cross-sections were made by linearly mounting fiber strands in plastic tubes and cut end of the tube was inserted into a cutting device and a clean cut was made by using a new razor blade. For longitudinal surface studies, fibers were horizontally mounted. The slices were mounted onto copper stubs using double side sticking tape and were coated with gold on their cut surface to be observed using SEM.