A disposable razor blade can be resharpened or honed by using the proper honing materials.  A virgin razor blade edge is sharpened to within one thousandth of an inch.  As the blade wears, the edge becomes uneven or jagged on a microscopic level.  Eventually the blade becomes so dull that it is unuseable and usually discarded.  Below is a magnified picture (225X) of a sharp razor blade next to a worn blade.  By using the correct abrasive pad that has filtered media at the nano scale, the edge can be revived to flat, smooth, and sharp.  Stroking the blade on this type of media restores the razor edge to within one thousandth of an inch.  A picture of the nano particle pad is shown below.  Using a pad like this is both economical and ecological.  The Environmental Protection Agency estimates that two billion disposable razors make their way into landfills every year and a typical name brand disposable razor blade or cartridge costs $2.00 each.  Disposable razors can be reused and resharpened.  Purchase a pad like this for a few dollars using this search Disposable Razor Sharpener Pad