The reader evaluates the publication, but does not always value the work of the designer who made sure the experience of reading was comfortable and pleasurable. As Dębowski puts it:
Only after we go a level below, by looking at how the text appears on its own, will we be able to establish some basic physical properties which determine whether the book is easy to read or not.
The devil is in the details
First up: the font size.
Too small and people with weaker eyesight will have a problem with distinguishing the shape of the words. Too big and the entire thing will seem clumsy and ill-formed.
Second: the line spacing, or the vertical distance between the lines.
Again: too small will make it difficult for the eye to move from line to line. If the line spacing is too large, we will lose the sense of continuity of the text.
Third: the margins, or ‘how the block of text sits on the page, or rather on the centrefold’.
And a short math lesson:
A typical layout has the bottom margin twice as big as the top one and the outer margin twice as big as the inner one. The optimal proportions between the inner, top, outer and bottom margins equal 2:3:4:6.
The Polish edition of Keith Houston's 'The Book: A Cover-to-Cover Exploration of the Most Powerful Object of Our Time', 2017, photo: Karakter Publishing House
And a quick side note: in the Middle Ages, it was Catholic monks who were responsible for the survival of Europe’s written word. They valued silence, so when transcribing book after book, they could express their emotions only in the margins of the pages. In The Book: A Cover-to-Cover Exploration of the Most Powerful Object of Our Time, Keith Houston gave this example of their scribbling:
Writing is an excessive toil. The back hunches, the eyesight weakens, the sides and the stomach turn.