Disclaimer: this is a bit off-topic, but I'm thinking that TeX designers must have considered this at one point or another

Why do all pages in a book have to have exactly the same text width? (and font size, for that matter)

I understand that the Knuth-Plass strategy for making paragraphs is already a complex programming challenge, and apparently its natural extension for page layout is even more challenging (typically not implemented; a more naive approach is used instead). Adding new degrees of freedom might simply make the problem unsolvable in practice (my guess).

But perhaps not. The way I see it, the requirement that one page and the next have exactly (to a fraction of a mm) the same width and font size is not based on a typographic ideal (no human would see a difference when turning the page of a novel if the line width was half a mm wider, for example, or if the font scaled to 11.02pt). It is clearly a technical constraint inherited from previous technologies, and imposed from the start. As such, I wonder is the design of TeX thought of including it as a variable in the global problem. From a purely aesthetic point of view, I would rather let the page layout breathe ever so slightly than stretch much the inter-word spacing, which even in the best of cases happens too often to my eyes. Of course there are cases (grid design applications, etc.) where this would not be appropriate, just as ragged-right vs justified text in different contexts.

Any thoughts/references along those lines?

Edit: in response to the (very reasonable) suggestion that "ideally you would typeset your content on a grid, such that the two sides of page would perfectly line up and the content would overlap", I want to clarify a couple of things (to make the question interesting):

  • I am not suggesting drastic or even visible changes, but very minor breathing, in the line of microtypography adjustments
  • printed pages are never exactly aligned (hence page bleed, etc.)
  • ideal paper is not see-through, and partial transparency is already a problem regardless of page layout (content will never line up, except for contrived examples of Lorem Ipsum)
  • computer screens display pdfs without this see-through inconvenience
  • I believe grid typesetting is but one strategy (albeit often the best), and in some specific designs perhaps not the optimum
  • 2
    it's largely tradition, based on the requirements of metal type. however, even if not constrained by metal, it's still likely that a paragraph might end on one page and continue on the next. so the flexibility you suggest might result in varying paragraph widths on the same page (assuming division into pages), or in adjacent paragraphs in a scrolling text. that might cause a reader to become slightly seasick, depending on how delicately it is applied. Apr 4, 2018 at 1:32
  • @barbarabeeton I do not follow: why would such a split paragraph have to keep a constant width? Would you impose a similar constraint in (exact) line spacing when a paragraph carries over? (other than ease of implementation for the algorithms, which are probably non-interacting)
    – user159867
    Apr 4, 2018 at 1:51
  • 1
    "Philosophically", the origin of TeX starts with the idea that there exist such things as "real books" (DEK's words) and the goal/ challenge is to approach their quality using computer means. There are centuries of typographic tradition saying that page widths should not vary randomly. If you're willing to throw out centuries of typographic practice a great many new things become possible, but you may want to consult the opinion of experts first, about the aesthetics. Even "micro typography" is controversial, and e.g. Thanh's thesis touches on it too. Apr 4, 2018 at 1:59
  • Thanks for the interesting perspective. BTW I do have some knowledge of broader typography standards. Computerised typography was a quantum leap, just as type was to calligraphy. I see no reason to "throw away" anything, but only explore new possibilities offered by technology. A monk/scribe hand-writing a manuscript would have written around holes in the imperfect parchment, and no two pages would have had pixel-perfect sizing (whatever that means, now that content is virtual). I agree that aesthetics implications may be good or bad, but is this a reason to dismiss the idea?
    – user159867
    Apr 4, 2018 at 2:11
  • No not dismissing; I think it's an interesting idea, along the same lines as microtypography (letter-spacing, glyph scaling, etc). (BTW I didn't give references earlier to it being controversial; I was thinking of this and this.) Was just explaining why it's unlikely that TeX's original designer would have considered this. (Apart from of course technological constraints of the time: limited memory, slow computers etc.) Apr 4, 2018 at 3:48

1 Answer 1


The page dimensions are actually very important because ideally you would typeset your content on a grid, such that the two sides of page would perfectly line up and the content would overlap. See

Here is an example picture of a double page where the grid is broken (taken from Ralf de Jong and Friedrich Forssman, “Detailtypografie”, Verlag Hermann Schmidt, 4th edition (2002)):

enter image description here

As you can see the lines from back will shine through to the front and distract while reading. Therefore it is very important to keep the page dimensions.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .