USPS

The stamp will sell for 41 cents and will remain valid for first-class postage regardless of future rate increases.

WASHINGTON - The "forever" stamp will go on sale Thursday, with an opening day ceremony at the Liberty Bell in Philadelphia.

The stamp, which carries an image of the Liberty Bell, will sell for 41 cents and will remain valid for first-class postage regardless of future rate increases.

The current 39-cent price for first class mail rises to 41 cents May 14, but buyers can use the forever stamps before that if they wish.

The stamps will be sold in booklets of 20 and postal officials said there is no limit on purchases.

When postal rates go up in the future, the cost for the forever stamp will also rise, but old ones will still be valid for mailing a letter.

The forever stamps are expected to remain in sale, well, forever.

But while postal officials expect them to be popular with consumers, they also think commemorative stamps that feature special subjects will continue selling well. Commemoratives, which are sold for limited periods, include such seasonal holiday stamps, flowers, landscapes and commemorate famous people and events.

The post office will also continue to offer "definitive" stamps at a particular rate. For first-class rates, for example, the U.S. flag has been used repeatedly in different designs and is popular with buyers.