The filing fee is only $45, so applying for a copyright should be done as a matter of course whenever possible. With respect to inventions, you should be thinking about getting a patent of some kind. The options are getting a utility patent, getting a design patent or both.
Height and weight and size for a calico cat? The colour of the cat's coat does not depict its overall shape and weight. The average weight of a cat is usually about 8 - 16 pounds. Cats average about 23 - 25cm in height and 46cm in body length, not including the tail.
The height of a standard one gallon paint can is 7 3/4 inches. The metal paint can was invented in the late 1800s, and the tight fitting lid was the most important feature. Edit