Among our modern stamps, which are mostly canceledby machines, it is very unusual to find the postmarkitself upon the stamp because the machine is set up sothat the postmark will fall some distance to the left ofwhere the stamp is usually placed. Hence collectors seekto obtain such postmarks, especially on commemorativestamps, by placing the stamp far to the left on theenvelope. When this is done "just so" and the envelopeis fed into the machine "just right," the postmark willfall exactly in the center of the stamp. Such cancellationsare called by collectors "socked on the nose" and not afew philatelists make a specialty of such postmarks.