A cover mattress is a decorative mattress considerably just like a four-poster bed. A typical canopy mattress normally features posts at each of the four corners extending four feet high or more above the mattress. Ornate or ornamental material is often draped across the upper house between the posts and a strong swath of material might create a ceiling, or canopy straight over the bed.
A four-poster mattress is a mattress with four vertical columns, one in each nook, that help a tester, or upper (normally rectangular) panel. This tester or panel will often have rails to permit curtains to be pulled across the bed. There are a variety of antique four-poster beds extant relationship to the sixteenth century and earlier; many of these early beds are extremely ornate and are made out of oak. An instance of such an early sixteenth-century four-poster resides in Crathes Fortress, which was made for the original castle owners in the Burnett of Leys family.