Silk is not particularly susceptible to wrinkling, but it can be easily wrinkled when folded in a drawer or stowed in a tight suitcase. Silk is a natural fiber, which means it's not as wrinkle-resistant as other fabrics made from synthetic fibers like polyester or nylon. If your silk sheet or silk duvet cover is wrinkled, the wrinkles may look exaggerated as most silk fabrics, such as mulberry silk, are known for having a very smooth surface.
If you fold or roll your silk clothing when you are not wearing it, expect some wrinkles to appear. If you fold silk and store it in a drawer or on a shelf, possibly under the weight of other folded garments, you will certainly see wrinkles when you take it out to wear it.
The best way to avoid wrinkles in your silk clothing is to lay it flat or hang it on a hanger when you aren't wearing it. To prevent your silk garments from wrinkling while in storage, you should hang them as often as possible. Hanging your silk pajamas, silk shirts and silk scarves will prevent new wrinkles.