The most commonly used gasket materials can be listed as: fiber, rubber, metal and composite laminate.
About Seals
Fluids
Sealing fluids are generally made of rubber or fibrous materials. Rubber comes in various forms (sheet, molded, O-ring, coated, etc.). Fibers are usually a sheet material and come in various forms depending on the factors of the joint. Composites can be a combination of rubber/fiber/metal, usually a laminate suitable for fluid sealing, with a metal core for support.
Gases
Typically, metal or composite materials are used for exhaust applications and other high temperature gas sealing joints. These resist degradation over time due to heat exposure, flange movement and thermal cycling, and maintain the seal. Metal gaskets require very smooth flange conditions, while composite products are more tolerant of rougher surfaces. In composites, the metal core provides support and, along with the barbed product, provides mechanical bonding. Composites also tend to be the most forgiving in terms of flange flatness, surface irregularities and varying flange loads.
Another question to ask - what are the other details?
Let's talk details
Other details to consider when selecting gasket materials are: quantity and method of manufacture. For small quantities gasket manufacturing methods such as flash cutting, waterjet and laser cutting can be used instead of investing in tools or dies to cut the part.
Decisions
Each of these gasket materials has its advantages and disadvantages. Each of these materials has performed well in certain applications, so it is important not to use one material for all sealing points and try one material simply because "it has worked well for us in the past".
Bonded Seal 