By Henry Gitner and Rick Miller

Many Great Seal of the United States Official stamps issued from 1993 on are getting harder to find in mint never-hinged condition.

The coil stamps are particularly difficult. Few dealers or collectors put these stamps away in quantity at the time they were issued.

The next-to-last to be issued, the 41¢ coil stamp of June 25, 2007 (Scott O162), is a good one to look for. We think it is undervalued in the 2016 Scott Specialized Catalogue of United States Stamps and Covers, at only $1 for a mint never-hinged single.

Dealers are paying more than face value for these Official stamps, which means they are selling them for more than $1.

Plate-number strips of five are valued at $8 in the Scott U.S. Specialized catalog, and are a very good buy at that price.

First-day covers are valued at just $2.10, but they are surprisingly scarce. Probably only a few thousand were serviced. Cacheted FDCs bearing plate-number strips of five are likely to be really scarce.

Now is the time to make sure that your modern Official collections are complete, because these stamps will become more expensive as time goes on.