Clarinets also come in resin and wood. They also are made in a variety of sizes, all the way up to the huge contrabass clarinet. The preferred wood for modern clarinets and other larger wind instruments is grenedilla wood, an exotic dark African wood which is somehow perfectly "aged" to be suited to resonate sound in a wind nstrument. It has a consistency to it's grain and has a density which yeilds a rich dark tone. Some clarinets are constructed of rosewood, which has a beautiful color, but it doesn't have quite the same quality to its sound. And a lot of older clarinets were made of boxwood, another dense hardwood.

Another important part of the clarinet which is made from polymers is the pads which cover many of the tone holes when the apropriate keys are pressed. If the pads are absent or damaged the sound sound can be severely impaired. So what are pads made of exactly? Find out more here.
A student clarinet made from ABS resin A really old clarinet made from boxwood
Here is a clarinet and its boxwood and ivory predecessor, not really much difference except the complexity and amount of metal hardware.

But the thing that makes a clarinet make sound is the reed. Reeds are made of cane which is carefully cut and shaped. Cane is a tough, bamboo-like stuff - a form of cellulose with long straight fibers.
cane which is made into reeds clarinet reeds
The clarinet is a single reed instrument. To produce a sound one
must use a cane reed in the mouthpiaece
A single reed is placed in the ligature of the clarinet mouthpiece and when it is blown correctly, the reed vibrates against the mouthpiece and makes a smooth hum which vibrates the whole clarinet body to make that nice clear tone which we all hope to hear when someone plays a clarinet. Though canewood is pretty tough, the edge of a reed can be easily damaged, and if a reed is damaged the sound might not be what we hoped for, like a buzzing in the tone or the sound of escaping air. In this case the reed must be replaced or readjusted.

Synthetic plastic reeds have also been produced. And though they are not as easily damaged, and are technically "more consistent" they still don't vibrate quite as well as the real thing. Supposedly synthetic reeds are getting closer and closer to sounding like the real thing.