Keep that Paper Hanging: Dealing with Humidity
Your wallpaper's worst enemy (after a child with a marker in his hand) is humidity. High humidity in a room (like a bathroom) can cause the paper to start peeling at the seams. So apply a coat of clear varnish at the seams to seal them and help prevent the moisture from seeping in. You'll find a non-gloss polyurethane varnish in the paint department of your local hardware store.