Left: An example of an acid free “book card,” which helps staff know where to shelve books without placing damaging adhesive stickers on book spines, and red cotton ribbon secures a loose book cover on C.S. Lewis’s personal copy of "Plutarch's Lives." Right: Making photocopies and scans of original documents helps preserve them by allowing access to the content without causing any handling damage. A copy can look almost identical to the original document itself. Can you tell which image above is of the original bank cheque, and which is of the color photocopy? (Hint: The copy has a small black triangle near its lower right corner.)