Scott Catalog # 4146 - 4150 / FDCO Exclusive First Day Covers.
Set includes: 4146 Diamond Head Lighthouse / 4147 Five Finger Lighthouse / 4148 Grays Harbor Lighthouse / 4149 Umpqua River Lighthouse and 4150 St. George Reef Lighthouse.
The Collectible First-Day Digital Color Postmark is an official digital postmark bearing the first-day-of-issuance-date containing an image that relates to the stamp design with the words "FIRST DAY OF ISSUE."
The cachet (image) was made on a computer and printed on high-quality envelope.
