Bed Linens Etc., has bunk bed caps for you twin extra long bunk bed. Our xl twin bunk bed comforters are made with an elastic band along the bottom edge, and guaranteed not to slip from the mattress. Our 200 thread count Twin XL bunk bed comforter is made with a 50/50 cotton poly blend, and is is available in 27 different colors. Whether you're decorating a girl's room or a boy's room, you're sure to find the perfect shade in our bunk bed bedding collection. Most people also buy a coordinating pillow sham to go with bunkie.