Answer:
What is lighter than what it is made of?
I grow for a surface, even if you cut me. I continue to grow even after death.
Voiceless it cries, Wingless flutters, Toothless bites, Mouthless mutters. What is it?
It's in your hand though you can not feel it. Only you and time can reveal it.
The itsy bitsy teeny weeny yellow polka dot variety is quite popular.
I am rarely touched but often held. If you are smart you'll use me well. What am I?