It took you months and months — or years and years — to tear down every shred of wallpaper in the house and get all the rooms painted. And now you’ve heard wallpaper is “in” again.

Just when you mastered the art of sponge painting, wallpaper makes a comeback. No kidding. Claret-colored damask, faded fruit and all those old ivy prints from the ’40s and ’50s are actually ...