•  Mechanical attributes such as durability, elasticity/flexibility to tolerate pressure/impact, and strength and toughness.
•  Firm sealing, leakproof, resistant to moisture, water vapor, gas, light, odor, and heat are examples of insulation qualities.
•  Features of safety such as non-toxicity, resistance to corrosion, ability to keep out insects and pests, and antimicrobial properties,
•  Processing characteristics include printing compatibility, ease of use in automated processes, and appropriateness for processing into a variety of goods.
•  Additional factors include a large number of suppliers, simplicity in handling, affordability, and simple availability of the raw ingredients.

Metals The metal caps are usually made of steel and aluminum. They have a wide range of temperature tolerance and are resistant to fracture from impact. The steel caps are usually coated with an anti-corrosive coating of chrome plate or tin plate. Other materials like plastisol, pulp/aluminum Foil, or solid PE (polyethylene) are also used.

Liners Liners are the coatings that are applied to the caps. The type of product determines which liners are best for a certain purpose, such as moisture barrier, chemical resistance, safety, or leak prevention. Three-ply foam, polyethylene foam, Teflon PTFE, foil, plastisol, pressure-sensitive foam liner, induction liner, polyvinyl, and poly seal are among the several types of liners.