### 3.1.83 PaperColumn

PaperColumn objects are created by: Paper_column_engraver.

Standard settings:

> `allow-loose-spacing` (boolean):

>   `#t`

>   If set, column can be detached from main spacing.

> `axes` (list):

>   `'(0)`

>   List of axis numbers. In the case of alignment grobs, this should contain only one number.

> `before-line-breaking` (boolean):

>   `ly:paper-column::before-line-breaking`

>   Dummy property, used to trigger a callback function.

> `font-size` (number):

>   `-7.5`

>   The font size, compared to the ‘normal’ size. `0` is style-sheet’s normal size, `-1` is smaller, `+1` is bigger. Each step of 1 is approximately 12% larger; 6 steps are exactly a factor 2 larger. Fractional values are allowed.

> `horizontal-skylines` (pair of skylines):

>   `ly:separation-item::calc-skylines`

>   Two skylines, one to the left and one to the right of this grob.

> `keep-inside-line` (boolean):

>   `#t`

>   If set, this column cannot have objects sticking into the margin.

> `layer` (integer):

>   `1000`

>   An integer which determines the order of printing objects. Objects with the lowest value of layer are drawn first, then objects with progressively higher values are drawn, so objects with higher values overwrite objects with lower values. By default most objects are assigned a layer value of 1.

> `skyline-vertical-padding` (number):

>   `0.08`

>   The amount by which the left and right skylines of a column are padded vertically, beyond the `Y-extent`s and `extra-spacing-height`s of the constituent grobs in the column. Increase this to prevent interleaving of grobs from adjacent columns.

> `X-extent` (pair of numbers):

>   `ly:axis-group-interface::width`

>   Extent (size) in the X direction, measured in staff-space units, relative to object’s reference point.

This object supports the following interface(s): axis-group-interface, font-interface, grob-interface, item-interface, paper-column-interface, separation-item-interface and spaceable-grob-interface.

#### Internals Reference v2.18.2 (稳定分支).