The "feather pillow police" would tell you the correct way is to have the pillow covered in ticking, then put the pillow in a pillow cover, white with a zipper on the end, and then put the pillow covered pillow into the pillow case of your choice. The ticking keeps the feathers inside the pillow. The pillow cover protects the ticking from oil and dirt that comes through the pillowcase and the pillowcase is decorative to match your sheets. When you see how hard it is to make a good ticking and to transfer feathers from one old pillow to a new pillow then you will appreciate the practical nature of having a cover to keep the ticking clean.