It’s your last chance to use up those “Star Wars” stamps and other 41-cent ones without tacking on extra postage — mailing rates go up Monday.

It’s also the last chance to buy the Forever stamps for 41 cents each. On Monday, they’ll cost a penny more, matching the rate increase for regular first-class mail.

Forever stamps are just what the name says — valid forever no matter what the current rate is for a first-class letter or bill. So even if stamps increase to $2 each, that Forever stamp you bought for 41 cents will still work to mail a letter.

Forever stamps can be purchased at the post office, at some stores, at banks that sell postage and through www.usps.com.

Also starting Monday, 2-ounce letters will cost 59 cents, and postcards will be 27 cents, both up a penny from current rates.

And the U.S. Postal Service will introduce some shape-based rates for unusual sizes of greeting cards and other mailings. For instance, some square greeting cards that recently have become popular will cost 62 cents, though stamps in that denomination aren’t available yet, according to USPS.com.

Express mail is changing to a new way of calculating rates by zones, so it will be cheaper to send items to nearby destinations. Other package rates also are changing.

For more information, call (800) ASK-USPS, go online to www.usps.com or visit your local post office.