Royal advanced pillow encasement creates an impenetrable barrier between you & the irritants ( Bed Bugs, Dust Mites & Allergens) that get in the way of restful sleep. Unlike other barrier fabrics, PristineTM is soft, breathable, and strong enough to withstand repeated washings. It's a woven fabric technology so effective, PristineTM was awarded the only patents in its category. Departments of Asthma, Allergy & Immunology at two leading Colleges of Medicine found that Pristine is an effective barrier to Bed Bugs, Dust Mites & associated Allergens that can cause allergic symptoms among sufferers of Asthma, Rhinitis & related respiratory problems. For best protection, encase all pillows, mattresses & box springs on your bed. Use ELF for Bugs Spray to eliminate insects naturally.