Context: Mechanical pulping yields almost a tonne of pulp per tonne of dry wood used, which is why mechanical pulps are sometimes referred to as "high yield" pulps. With almost twice the yield as chemical pulping, mechanical pulps is often cheaper. Mass-market paperback books and newspapers tend to use mechanical papers. Book publishers tend to use acid-free paper, made from fully bleached chemical pulps for hardback and trade paperback books.

Question: How many times more yield does the mechanical pulping process produce when compared to to the chemical pulping process?
Answer: twice

Question: What type of process is used to produce most paper used in paperback books?
Answer: Mechanical

Question: What level of acid is usually found in the paper used by book publishers?
Answer: acid-free

Question: What type of pulping yields nearly a tonne of dry wood per pulp tonne used?
Answer: Unanswerable

Question: What type of pumps are sometimes called low yield pumps?
Answer: Unanswerable

Question: Because it has a lower yield, what type of pulping is often cheaper?
Answer: Unanswerable

Question: Mechanical pulps are often more expensive than what?
Answer: Unanswerable

Question: What type of paper do mechanical pulps tend to use?
Answer: Unanswerable

Question: How many times more yield does the mechanical pulping process produce when not compared to to the chemical pulping process?
Answer: Unanswerable

Question: What type of process is used to produce least paper used in paperback books?
Answer: Unanswerable

Question: What level of acid is not usually found in the paper used by book publishers?
Answer: Unanswerable