The Lisp printer makes its determination of how to print an object as follows:
If the value of *print-pretty* is true,
printing is controlled by the current pprint dispatch table;
see Section 22.2.1.4 (Pretty Print Dispatch Tables).
Otherwise (if the value of *print-pretty* is false),
the object's print-object method is used;
see Section 22.1.3 (Default Print-Object Methods).