What percentage of page does/should a text occupy “inkwise”

Question

I am interested what is the total area of a book page that is occupied by text. Basically, how much ink do I need to spend to print a page with text.

I have experimented with different fonts like Bodoni, Helvetica and PT Serif:

And also PT Sans and PT Sans Extra Condensed:

Bodoni is a "modern" font, so it looks less dense than PT Serif and Helvetica. I have used some online tools to measure percentage of black color in the picture and it seems that Bodoni occupies 12% of the page, while PT Serif, PT Sans and Helvetica -- around 15%. PT Sans Extra Condensed -- around 22%.

If I switch to black series, PT Serif Black occupies approximately 20%, Helvetica Black -- around 25%. PT Sans Extra Condensed -- 40% (barely readable).

Are there any guidelines on how "dense" and "black" should the text be for the most comfortable reading? Very dense texts (printed with a condensed of bold font) are hard to read, while if a text is very "light", it is also hard to read it.

Answer 1

I do not think the percentage of ink text uses is ever a concern for a designer. At least not any designer I've ever known. In fact, this is the first time in my career I've ever heard of any such concern.

What is important is readability and legibility. Any percentage of ink used is not going to tell you whether or not text is readable and legible.

A condense black typeface will use more ink however it can be just as difficult to read as an extended thin typeface using less ink. There's no direct correlation between readability and the ink percentage text requires.

Text is typically free to use whatever percentage of ink it requires. There is no technical reason one need be concerned with ink percentage for text. It is never going to tell you if text is readable and legible. And even a full page of text is highly unlikely to hit pre-press caps of roughly 300% ink usage.

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I see this question akin to a cook asking "What percentage of salt should a dish contain?" - There is no "normal" or formula to use. Each and every dish has to be seasoned to taste. Relying on some given percentage simply means you will either over or under salt 99% of what you cook.

Answer 2

First off I enjoyed (and upvoted) your question- I thought about it off and on all day - so much so that I decided to voice myself. I am not aware of any studies which would indicate desirable or acceptable ink coverage percentages to aide in choosing a typeface. There may very well be such studies that would show some technical rules or guidelines. Following these rules or guidelines will not necessarily give you the "comfortable to read" text you are trying to find.

I find the observations you made regarding your sample typefaces to be accurate and although it is very subjective, I tend to agree with them. Design work certainly has some restraints in the form of general rules and guidelines but that is not nearly all there is to it. Designing includes working within many constraints while at the same time requiring creativity from the designer. Often the creativity is being able to succeed in working around all the constraints. If everything was done according to rules and guidelines I fear it it would look quite boring out there.

I suggest that rather than relying on a general rule or guideline that you explore what looks good to you. What you find readable and comfortable while still delivering the message you want. This is a part of the artistry of design work- the creativity of design work. It is the artistry of designs which makes them memorable.

So much here at GDSE we are dealing with the technical side of things. How to do certain things with the tools we are using. These are all very important endeavors. I find them quite interesting and it seems I am always learning something. I do miss that there is not so much focus on the creativity, the artistry of design work and would like to see more of this (difficult to incorporate this in a question/answer format that does not really want opinions).

Apologies that this turned into more of an editorial than an answer. I am a bit afraid I will get bombed for this- but, oh well.

Answer 3

I have seen this property of printed text referred to as "type color", "typographic color" or "grayness".

A lot of effort goes into making the grayness as even as possible. On this topic Hàn Thế Thành's dissertation, "Micro-typographic extensions to the TEX typesetting system" is a great read. It reaches back to the Gutenberg 42-line Bible as the ideal.

I haven't seen a discussion about the "best" value for overall grayness. Perhaps measuring the grayness of the Gutenberg 42-line Bible could be a starting point at least as valid as any other.