Stamps (Philately)/MULTI FRANKING
I believe that that is the correct term. multi franking. when one or more stamps of similar relationships are held on the same first day cover. Do they have any added value or do they actually decrease the value of the original subject that the stamps and cover was issued for? Also does it decrease or add to the value of a cover to send one already postmarked back in to be re stamped on an anniversary or add another stamp at a later date? For example. to have a post marked first day cover with James Dean, then to send it in when the Marilyn Monroe stamp came out (which ever came first). Does that hurt the cover or add to the uniqueness and thus higher resale value. I am thinking of creating some unique items of my home and would like to know which would have the best interest of future collectors and provide a much higher resale value. Yes. shameless capitalism, but honest and legitimate concerns, besides it gives stamp colectors something more interesting to collect
I don't collect or sell First Day Covers myself, but my understanding is that most FDC collectors tend toward solo use on tidy, uncluttered covers. But cover collecting is diverse, so I can't say for sure that the multiple franking you describe would add or subtract value. But I suppose that in order for it to add value, you would need to find someone to buy your cover that thinks your addition is as cool or cooler that you do.
I deal in United States Stamps
American Art Glass
and Halloween Costumes!