Thin Blue Line American Flag Rustic Wood 37"x20" Handmade Flag with Water Base High Gloss Polyurethane Finish. Hanging Hardware Attached. Each flag is individually made by me. After each stripe is cut to size, they are lightly torched and stained. The flag is then assembled and lightly sanded to highlight the natural wood grain and knots. Once I'm satisfied, I apply an oil based or water based polyurethane finish. The oil base leaves a slight yellowing to the white stars and stripes, giving it a more aged appearance. The water based poly dries clear without any discoloration. Both effects look great!