### 4.6.1 Displaying spacing

To graphically display the dimensions of vertical layout variables that may be altered for page formatting, set `annotate-spacing` in the `\paper` block:

```\book {
\score { { c4 } }
\paper { annotate-spacing = ##t }
}
```

All layout dimensions are displayed in staff-spaces, regardless of the units specified in the `\paper` or `\layout` block. In the above example, `paper-height` has a value of 59.75 `staff-spaces`, and the `staff-size` is 20 points (the default value). Note that:

 1 point = (25.4/72.27) mm 1 staff-space = (`staff-size`)/4 pts = (`staff-size`)/4 * (25.4/72.27) mm

In this case, one `staff-space` is approximately equal to 1.757mm. Thus the `paper-height` measurement of 59.75 `staff-spaces` is equivalent to 105 millimeters, the height of `a6` paper in landscape orientation. The pairs (a,b) are intervals, where a is the lower edge and b the upper edge of the interval.