Historically, the first caps were made with a friction closure (those that are generically defined ''[[slip cap]]s''), with the cap that fits on the body. There are different variants of this type of choice, depending on the way in which the joint is made; the two main classes are the so-called ''[[cone cap]]'' (conical section cap) in which the interlocking surface is a truncated cone, and the so-called ''[[straight cap]]'' (cylindrical section cap) in which the interlocking surface is cylindrical, among the latter there are then the so-called ''[[tapered cap]]'' (conical or tapered cap) in vogue at the end of the 19th century. | Historically, the first caps were made with a friction closure (those that are generically defined ''[[slip cap]]s''), with the cap that fits on the body. There are different variants of this type of choice, depending on the way in which the joint is made; the two main classes are the so-called ''[[cone cap]]'' (conical section cap) in which the interlocking surface is a truncated cone, and the so-called ''[[straight cap]]'' (cylindrical section cap) in which the interlocking surface is cylindrical, among the latter there are then the so-called ''[[tapered cap]]'' (conical or tapered cap) in vogue at the end of the 19th century. |