I want to test the ability of students to read a passage and answer questions about it. Could you please come up with a good question for the passage "The general effect of the water content upon the wood substance is to render it softer and more pliable. A similar effect of common observation is in the softening action of water on rawhide, paper, or cloth. Within certain limits, the greater the water content, the greater its softening effect."? 

What writing material do we get from the softening effect?