Adjusting fontsize so text fits with multiple columns

einmaulwurf · November 19, 2025, 1:20pm

I’m building a report where I often have an image or a table together with some explanatory text on one page. I have the following function to help me scale the text down so it fits onto that page without overflowing:

/// Scales down text by adjusting the fontsize, until the text fits within the container.
#let scale-text(body) = layout(size => {
  context {
    let font_size = text.size
    let height = measure(
      block(width: size.width, text(size: font_size)[#body]),
    ).height
    let max_height = size.height
    
    // Reduce font size until content fits
    while height > max_height {
      font_size -= 0.2pt
      height = measure(
        block(width: size.width, text(size: font_size)[#body]),
      ).height
    }
    
    block(
      width: 100%,
      text(size: font_size)[#body]
    )
  }
})

I use it like this, for example:

#set page( 
  paper: "a4",
  flipped: true,
) 

#grid(
  columns: (3fr, 1fr),
  gutter: 2em,
  rect(fill: red, height: 100%, width: 100%), // Here could be the image or table
  scale-text()[#lorem(500)] // The explanatory text that should fit onto that same page
)

But now I would like this to work with multi-column layouts as well, so that the text wraps in the columns but doesn’t overflow:

#grid(
  rows: (3fr, 1fr),
  gutter: 2em,
  rect(fill: red, height: 100%, width: 100%),
  columns(3)[#scale-text()[#lorem(500)]]
)

However, the text is scaled down too much and put completely into the first column. Is there a way to do that properly?

Thanks

Y.D.X · November 19, 2025, 2:04pm

Perhaps putting columns() inside scale-text?

/// Scales down text by adjusting the fontsize, until the text fits within the container.
#let scale-text(columns: 1, gutter: 2em, body) = layout(
  available => context {
    let font-size = text.size
    let height = calc.inf * 1pt

    // Reduce font size until content fits
    while height / columns > available.height {
      font-size -= 0.2pt
      height = measure(
        text(size: font-size, body),
        width: (available.width + gutter) / columns - gutter,
      ).height
    }


    set text(size: font-size)
    std.columns(columns, gutter: gutter, body)
  },
)


#set page(paper: "a4", flipped: true)

#grid(
  columns: (3fr, 1fr),
  gutter: 2em,
  rect(fill: purple, height: 100%, width: 100%), scale-text(lorem(500)),
)

#pagebreak()

#grid(
  rows: (3fr, 1fr),
  gutter: 2em,
  rect(fill: aqua, height: 100%, width: 100%),
  scale-text(columns: 3, lorem(500)),
)