As you complete squares in your grid you can start to erase your grid lines. When all of your grid squares have been completed and the grid has been completely erased, you may need to go back and make slight adjustments to shading and details especially in areas that may have been accidentally erased or smudged when you were removing the grid lines. Clean up smudges, smears, and grid lines that remain. Once you are satisfied with your drawing you can spray it with a fixative and let it dry over night. (Make sure that you keep the poster board secured to the drawing board while you spray the fixative and let it dry. This will help minimize rippling and curling.) Once dry you can carefully remove the masking tape from the border, and your masterpiece is ready for framing and displaying.