Place the board with one 16-by-16-inch side flat on a work surface. Form the flexible curve ruler from two diagonally opposing corners of the board in a graceful curve. This is for the front edge of the shelf. The sides that form the right angle opposing the curved edge will fit flush against the walls in the corner. Trace the shape of the curve along the ruler’s edge onto the board with a pencil once you are satisfied with the shape of the curve.
Lay the board flat on the table of a band saw. Guide the board through the saw while following along the pencil line to cut out the curved edge. Move the board through the saw blade just fast enough to allow the blade to cut the wood.
Sand the cut edge of the shelf board with a fine-grit sanding block in the direction of the wood grain until it is smooth.
Wipe off the dust left from sanding using a tack cloth to ensure a clean wood surface right before you are ready to apply a finish to the shelf board.
Spray an even coat of lacquer onto the shelf board. Allow the lacquer to dry at least 4 hours and apply a second coat. Allow the final coat of lacquer to dry 24 hours.
Hold the shelf in the corner at the desired height. Mark the bottom edges of the shelf onto the wall with a pencil. Position one shelf bracket on each wall in the corner so that the top edges of the brackets align with the pencil markings. Space the brackets 8 inches out from the corner against each wall.
Drive the screws that were included with the brackets through the bracket’s mounting holes into the walls using a screw gun. Lay the shelf on top of the brackets. Ensure that the edges are flush against the wall. Drive the screws through the mounting holes into the bottom of the shelf board to secure it in place.