A structure holding spine settings. See the Folding Lines and Spines topic for details.
bleed sets offset in points for the folding line depending on its orientation. It is a top/bottom offset for the vertical line and a left/right offset for the horizontal line.
spine fill color.
defines whether the folding line is vertical. If true, then the line is vertical, otherwise it is horizontal.
margin defines absolute or relative location of the folding line on the product in points or percent. For vertical lines it defines the x-axis offset from the left edge. For horizontal lines it defines the y-axis offset from the top edge of the product. To set relative offset in percent, add the percent sign to the number.
pen configures the outline of the folding line.
line alt color
line main color
line dash step in pixels
spine width in points.