What is the best type of elastic?

Could you please elaborate on what you mean by "the best type of elastic"? Elasticity is a property that varies depending on the material, intended use, and desired performance. For instance, if you're looking for elastic for clothing, you might prioritize stretchiness, durability, and comfort. On the other hand, if you're designing a medical device, you may prioritize biocompatibility and the ability to withstand sterilization. Can you provide more context so I can offer a more specific answer?