Question: As a puzzle author, I often write puzzles with red ink and then test-solve them with pencil. What would be the most efficient way to remove the pencil and blue gridlines from the paper to leave only the red puzzle clues behind?

Answer: 
As one who has typeset a thick mathematical book (written by various contributors), I would make two points in favour of Computer Modern.

First, the lower-case italic *v* and the lower-case Greek *ν* are clearly distinguished.

Second, parentheses rise higher than ascending letters, so that items in parentheses look more fully enclosed than in other fonts (e.g. Times Roman).

It is sometimes said that headings in Computer Modern make it too obvious that a document was typeset in (La)TeX. But this is easily overcome by setting headings in a contrasting font, e.g. using the "sectsty" package. When Computer Modern is used as a body font -- if I may lapse into opinion -- I find it reasonably neutral.

### P.S. (23 January 2020)

I typeset **[this paper](https://doi.org/10.5281/zenodo.3563468)** in a version of Computer Modern, using the `sectsty` package to set headings in sans-serif, plus the `helvet` package to change the standard sans-serif typeface to the Helvetica-like "Nimbus Sans L". The relevant lines from the preamble are:

```
    ⋮
\usepackage{cmlgc,amssymb,amsmath}
  \DeclareTextCommandDefault{\textbullet}{\ensuremath{\bullet}}
\usepackage[scaled]{helvet}
\usepackage[T1]{fontenc}
    ⋮
\usepackage{sectsty}
  \allsectionsfont{\sffamily\raggedright}
    ⋮

```

Notes:

* The appearance of the preview is somewhat browser-dependent; you might need to download the PDF in order to see it correctly.
* If your setup uses cm-super fonts by default (my latest setup doesn't), then you won't need the `cmlgc` package.
* *Mea culpa*:  I was using the `cmlgc` version of Computer Modern for the first time, only to discover later that it does not scale optimally. If you use `lmodern` instead, you get a significant increase in the width, and a barely discernible increase in the darkness, of footnote-sized characters. One possible reason for using `lmodern` instead of cm-super is that `lmodern` gives a lower `\textasciitilde`.
* Modifying `\textbullet` sometimes gets rid of font-error messages.
* The `scaled` option to `helvet` adjusts the size so as to allow mixing with the serif font in text.
* The `\allsectionsfont` command, provided by `sectsty`, modifies all section headings at once (which is probably what you want).
* Yes, apparently `helvet` needs to come before `sectsty`.
Yes it is! It's well-designed as a text font, and it has small caps and text figures. But it was designed a long time ago and there are a few oddities: - and – are at very different heights and some modern currency symbols are a problem, the € was clearly not added by the font's original designer and ₹ is missing (a common test of fonts to see if they've been remastered recently, that one, by the way). And it has some bonuses many pro fonts don't: the upright italic can allow more creative typography, and I really like the "classical" italic with serifs at the entrance to characters and the non-extended bold, both feel very practical and modern to me, maybe better than the defaults, while the wider standard bold looks great in headings, and in tracked out small caps too.

A few possible alternatives. [STIX Two Text](https://www.stixfonts.org/) is based on Times New Roman, so it's a lot more anonymous, less defined by the style of the nineteenth century, and because it's based on the smaller sizes of Times New Roman's metal type it's particularly good for small sizes. It's free. [Commercial Type's Brunel](https://commercialclassics.com/catalogue/brunel) is in the same style, but designed for high-style fashion magazines. So it's got optical sizes for super-large headings, and pushes the design further with bolder-than-bold weights, tons of flourished characters and [piles of niceties](https://commercialclassics.com/uploads/4800048/156320577664/Brunel_Text-family.pdf) like small-cap, proportional and tabular figures. [HTF's Surveyor is similar](https://www.typography.com/fonts/surveyor/how-to-use), and it's particularly strong in the lightest styles, although if it matters to you it doesn't have text figures.