Clue: Material popped up three books with real worth initially condemned (6,4)
Answer: BUBBLE WRAP
Explanation: Definition: Material popped
 **Anagram of**(… condemned) [UP + BBB(3 x abbrev. for "book") **plus**(with) REAL + **1st letter of**(… initially) "worth" ].
Defn: Packaging material of plastic with air bubbles that can be popped/burst.