This question just can't leave me

Its a dark wood

Why would they be made of plastic? They look like dark wood and feather.

They look like green plastic to me...

He's a Elf and middle earth is filled with magic so he could have used a magic spell to make them

Do people really expect them to make every single tiny detail accurate to the place the movie is set in? C'mon guys, it's still a great movie and in the end it's just the bottom of an arrow.

The elves must have made them with some magical elf material that looks like plastic.

It's Orc bone and feathers. Nah, just kidding, probably wood. Although I wouldn't put it past him...

I'm sure the material is authentic. Watch behind the scenes footage and they talk about all the crazy detail that went into every costume and weapon and just everything.