Best font for large amounts of text on A4 page

What is the best font for readibility and economy (=maximum number of characters per page) given following specifications:
-page size A4 with 8 mm margins on left and right and 12 mm top and bottom
-assuming a page with just text, the font should give a total of 11500-12000 characters per page (including spaces)
-either 3 or 4 columns with a 3 mm separation between each column
-should be readable under suboptimal lighting conditions.

This is just for hobby without any professional or commercial pursuits. I managed to get about 11500 characters on an A4-page by using 0.9 line spacing and Adobe Jenson Pro Semibold 9pt and 3 columns. That with just MS Word.

Often it’s considered 60 to 70 characters per line.

But other things come into play.

Optimal leading is considered at 120percent of the font size. So 10 pt font would be 12pt leading.

It can be a very visual thing. You could easily have 110% leading and still have easy readability.

It will come down to your font choice and different fonts have different ascender, x, descender, widths, heights and all that.

Important thing about font choice is the tone it sets.
Times is often used for newspapers. Palatino for books… Etc

Choosing sans serif or serif etc

There’s a lot to think about. I think mostly a column width of between 60 to 100mm for a multicolumn layout is ideal and going above 100mm could make line.lenghts too long.

A font with a large x- height is key for readability at smaller sizes.

Readability is almost science :wink:

Readability and legibility are subjective and depend on many different variables that one must consider. Readability can’t be reduced to a simple conclusion of one choice always being better than another. In other words, your question presupposes an answer when there is no definitive answer.