Things You'll Need
Instructions
Observe whether the glue is clumpy or dry and flaky.
Scrape the glue gently with a craft knife if it is dry and flaky. Do this slowly and gently so that you don't scratch or tear the postcard.
Soften the glue if it is clumpy by dabbing on some glue solvent, which can be purchased at most hardware stores. Apply a few drops of solvent to a clean cloth and then dab the cloth onto the glue.
Rub the glue off with a cotton swab after it has been dabbed with the solvent.