A OBW is a One Block Wonder--a type of quilt where you use just one fabric, usually with a large print. You make hexagons or octagons using different parts of the print. It produces a kaleidoscope effect and can make some stunning quilts. If you go to "Search" and type in OBW, you will get lots of results with information and photos. There is also an awesome tutorial done by Cutebuns that takes you step by step to create a OBW.