Film -

The material the head is made from is probably the biggest contributor.

Calfskin- Calf was the original material, and it produces a warm, dark sound. The problem is that it is difficult to keep in tune, as it is effected by humidity and temperature changes. It is still used today in Concert Bass Drums, Timpani, Tambourines, and by some jazz drumset players.

Mylar- The original "all weather" film was first developed in the 1950’s by the Evans company, and popularized by Remo. It is by far the most common material today, and is used in every venue for nearly every application in percussion. The color of the Mylar film also affects the sound.

White (smooth)- was the original film. It produces as clean, attack-heavy sound.

Clear- is the most common today. Many drummers prefer it for its cosmetics. Produced a midrange sound, which some feel is "harsh" or "crisp".

Black- Produces more highs, more of a "boingy" sound.

Other transparent colors- Generally produce similar sound to clear films. These were more prominent a few years ago.

Kevlar- Originally used in making bullet-proof vests, Kevlar was developed as a drumhead material to combat the rough wear that drum corps were putting Mylar heads through. As it is bullet-proof, the players could not dent or tear it, and therefore it made for excellent durability. Some drumset players have used it on full kits, and some on snares, but it is generally not considered a good all purpose choice for two reasons. Due to its extreme durability and tensile strength, it has a huge amount of rebound, and if not controlled properly with correct technique, Kevlar heads can be a killer on hands. Tendonitis and Carpal Tunnel Syndrome are by-products of extended use. Additionally, it doesn’t have a very resonant or tonal sound, so Kevlar is usually avoided for instruments other than snare drums.