One stamp on each of the first 8 of 10 panes of the U.S. Celebrate the Century series is engraved (intaglio printing). However the last two panes (1980s and 1990s) in the series do not have an engraved stamp. Whaaat???
Celebrate the Century Stamps using Intaglio printing
| Sheet Info | Intaglio stamp | Image (front) | Image (back) |
| 1900s Scott #3182 DOI: 3 February 1998 Denomination: 32¢ | Gibson Girl Scott #3182m |  |  |
| 1910s Scott #3183 DOI: 3 February 1998 Denomination: 32¢ | Panama Canal Scott #3183f |  |  |
| 1920s Scott #3184 DOI: 28 May 1998 Denomination: 32¢ | Charles Lindbergh Scott #3184m |  |  |
| 1930s Scott #3185 DOI: 9 October 1998 Denomination: 32¢ | Empire State Building Scott #3185b |  |  |
| 1940s Scott #3186 DOI: 18 February 1999 Denomination: 33¢ | International Style (UN) Scott #3186k |  |  |
| 1950s Scott #3187 DOI: 26 May 1999 Denomination: 33¢ | Polio vaccine Scott #3187a |  |  |
| 1960s Scott #3188 DOI: 17 September 1999 Denomination: 33¢ | Man on the Moon (footprint) Scott #3188c |  |  |
| 1970s Scott #3189 DOI: 18 November 1999 Denomination: 33¢ | Videocassette recorder Scott #3189h |  |  |