Shell Gasoline porcelain sign features the iconic Shell Motor Oil branding and is made of porcelain. 19 3/4″ x 13″. And features the clam shell with large lettering. Whether you are displaying this sign as part of your collection in your man cave, shop, bar, or garage, or giving it as a gift, you can also browse my other auctions for more vintage gas, oil, aviation, automobile, motorcycle, and hunting signs. Vintage Shell porcelain sign. Bright colors w/ porcelain on both sides.