It depends on your goal and budget. Silk, especially mulberry silk, often scores higher for a luxurious feel, temperature regulation, and a smooth low friction surface for hair and skin, which is why many people choose a silk pillowcase.

Satin is a weave, not a fiber. Cotton satin can be a good middle ground because it feels smooth and is usually easier to care for, while polyester satin is often cheaper and shinier but may sleep warmer and build static more easily. If you want maximum softness and a premium experience, choose silk with a sufficiently high momme weight. If you want affordability and easy washing, a good cotton satin pillowcase is often more practical. Also consider the closure and fit, since those affect everyday ease of use.