I was exasperated by the smudging of the postmark ink on the glossy postcards, so I experimented with the non-FIP solution of using a label. Oh, well, I like it.
At least I can see the postmark, which ideally should have been from a post office in or near the park.
Anyway, I consider it as a modest salute/tribute/honor to Shenandoah, originating from Sterling, VA, near my home.
That postmark is from my own Mailer's Postmark Permit canceler, which uniquely identifies me as permit holder #67 (I should have had #1, I guess, but my pre-cancel application # to USPS was aggregated with the 66 bulk mailers from that zipcode).
"The most difficult thing of those three mentioned in the title is to create your own pictorial postmark, legal and valid for postage with your Post (USPS in my case - the United States Postal Service)."
Details here: http://dorinco.webs.com/