“dhwriting” pens on the Helium website, “All of us have probably received packages or envelopes that were posted with beautiful or otherwise very collectible stamps used to pay the mailing cost. Any stamp collector worth his or her salt feels a thrill a desirable stamp arrives this way, out of the blue. In some cases, however, those lovely stamps arrive badly defaced by postal employees using thick marker pens or ball point pens. Their value as used stamps might be fairly high if it were not for these hand …