Spray the bookcase with a gentle, non-abrasive cleaner. Wipe it down with a soft cloth and allow it to air dry.
Dip a 3-inch nylon brush into a clear sealant that is UV-resistant and waterproof. Coat the entire bookcase with this sealant and allow it to dry for 24 hours. Repeat with a second coat.
Measure the length and width of each shelf. Write down these measurements.
Cut a piece of rubber shelf paper for each shelf of your bookcase, as well as one for the very top of the bookcase.
Cut eight 2-inch pieces of two-sided tape for each piece of rubber shelf liner. Attach each piece to the sides of each corner of the liner. When finished, all the shelf paper corners will have "L" shapes of tape on them.
Press your rubber shelf liners onto each shelf, leaving the last liner on the top of the bookcase. This will further protect the bookcase from water, snow and hail damage.