Percale is a very popular fabric for pillowcases due to its high thread count. It is smooth against the skin, and washes very well. Percale pillowcases are available in varying thread counts and sizes, and are quite economical when purchased in bulk. Dacron (polyester) is a standard stuffing for pillows, but they are also available stuffed with foam cubes, memory foam, feather down, bamboo fibres, and even flax seeds.
The term “bolster” goes back to Old English, meaning “to stuff something until it swells up.” It was also used to describe any kind of long pillow — used, presumably, for the same purpose that an RMT might use one today.