-automatically. Also see @code{check-consistency}. This variable
-can also be set in a @code{\layout} block.
+automatically. Also see @code{check-consistency}.
+
+@code{line-width}s for individual scores can be specified in the
+scores' @code{\layout} blocks. These values control the width of the
+lines produced on a score-by-score basis. If @code{line-width} is not
+specified for a score, it defaults to the paper's @code{line-width}.
+Setting a score's @code{line-width} has no effect on the paper margins.
+Staff lines, of a length determined by the score's @code{line-width},
+are left-aligned within the paper area defined by the paper's
+@code{line-width}. If the score and paper @code{line-width}s are equal,
+the staff lines will extend exactly from the left margin to the right
+margin, but if the score's @code{line-width} is greater than the
+paper's @code{line-width} the staff lines will run over into the right
+margin.