To tan a deer hide, clean it before soaking it in an acidic saline solution. Allow the hide to dry somewhat, and oil it before softening it over a wooden sawhorse.
Thoroughly clean the deer hide by using a knife to remove any bits of flesh or fat. Coat the flesh side of the skin with non-iodized salt, and let it sit overnight before immersing the hide in water until it softens.
Prepare a large plastic container with approximately 2 gallons of water, 2 gallons of distilled white vinegar and 8 pounds of salt. Soak the hide for three days, stirring the solution occasionally. Prepare another solution using 4 gallons of water and 2 cups of baking soda. Transfer the hide into the baking soda solution, and soak it for about 40 minutes before cleaning it with water and patting it dry with a towel. Instead of using a vinegar solution and a baking soda solution, you can also soak the hide in a mixture consisting of 4 gallons of water, 2.5 pounds of salt and 1 pound of ammonia alum for four days.
Rinse the hide with water, and pat it with a towel or let it air-dry until not much moisture is left. Apply a tanning oil solution onto the flesh side of the skin. Cover the hide, and leave it overnight. The next day, rub the hide vigorously over a sawhorse until it feels soft and flexible. Use fine sandpaper to impart additional smoothness to the hide.