### 4.4.2 Vertical spacing between systems

Space between systems are controlled by four `\paper` variables,

```\paper {
between-system-space = 1.5\cm
ragged-bottom=##f
ragged-last-bottom=##f
}
```

When only a couple of flat systems are placed on a page, the resulting vertical spacing may be non-elegant: one system at the top of the page, and the other at the bottom, with a huge gap between them. To avoid this situation, the space added between the systems can be limited. This feature is activated by setting to `#t` the `page-limit-inter-system-space` variable in the `\paper` block. The paper variable `page-limit-inter-system-space-factor` determines how much the space can be increased: for instance, the value `1.3` means that the space can be 30% larger than what it would be on a ragged-bottom page.

In the following example, if the inter system space were not limited, the second system of page 1 would be placed at the page bottom. By activating the space limitation, the second system is placed closer to the first one. By setting `page-limit-inter-system-space-factor` to `1`, the spacing would the same as on a ragged-bottom page, like the last one.

```#(set-default-paper-size "a6")
\book {
\paper {
page-limit-inter-system-space = ##t
page-limit-inter-system-space-factor = 1.3

oddFooterMarkup = \markup "page bottom"
evenFooterMarkup = \markup "page bottom"
"page top" \fromproperty #'page:page-number-string }
"page top" \fromproperty #'page:page-number-string }
}
\new Staff << \repeat unfold 4 { g'4 g' g' g' \break }
{ s1*2 \pageBreak } >>
}
```