Microfiber

Synthetic material (artificial microfibers) that allows the sheet to be lightweight, warm, and fluffy.

Refers to the number of threads per square inch of fabric. An average thread count ranges between 200 and 400, while quality sheets usually start at 300 and can go up to 800 or more. Generally, more threads mean softer and more durable fabric, although beyond a certain point (e.g., 600+), the difference becomes less noticeable.