What Is The Most Expensive Fabric To Make? Your answer might be silk. Silk is filament fiber formed from silkworms, or the Bombyx mori. These worms are not really worms; they are caterpillars. For thousands of years, humans have mastered the art and science of silk production, which originated in China. Silk Pros & Cons Silk is extremely valued for its softness, its strength and its insulating properties. Silk is expensive due to the fact that it is a natural animal product, and producing silk requires an intensive labor procedure that involves monitoring and feeding the silkworms continuously. Rather a lot of effort is…