Fonts for technical reports
I'm building an MS Word template for my reports. I am not sure what to use for fonts. I see lots of reports from clients and others using Arial, Verdana, Helvetica, Times New Roman, Calibri, Cambrai, and Trebuchet MS. I personally like Trebuchet for tables and charts but do not fancy it for wording in a report.
What are your suggestions for fonts to be used in technical engineering reports? Add to that, what would you suggest the proper font-spacing, size, paragraph and line spacings for that font should be?
Welcome to GD. I don't think anyone here will go as far as recommending one typeface, because the choice is heavily influenced by personal taste and the current fashion in your community, but I can offer some guidelines.
First of all, don't use an unusual-looking typeface, nor one that has a definite "personality." As a rough rule of thumb for a non-designer, if you can instantly identify a particular font on sight, it's probably wrong for this purpose no matter how much you like it. If there seems to be one font that dominates in your company or field, you can do a lot worse than use that one.
As a matter of practicality, use a font that already contains any special or foreign language characters you need frequently. That may mean using the more modern OpenType fonts, rather than TrueType or Postscript Type 1, both of which are obsolescent.
For technical documents, the typography should cue the hierarchy of information clearly, through headings and subheads, but otherwise get out of the way. The text typeface must be a self-effacing carrier of information, never calling attention to itself, comfortable for extended reading. You also don't want or need to buy special fonts (except for math or other special purposes). This implies sticking with Jenson, Caslon, Times, Garamond, Palatino and similar serif faces; or readable sans such as Myriad, Frutiger, Avenir (not Helvetica or Arial for body text, in my opinion -- they tend to "glare" when printed in full black).
A good general-purpose combination that's often recommended is a sans for headings and a serif for text, or vice versa, to provide some contrast. Match them by comparing the proportions of the lower case n, m, h and o and pair fonts where these are similar. Very different proportions tend to look like an uncomfortable mismatch, like wearing two socks that aren't the same color.
Don't use type with very fine serifs, especially if you're outputting to an inkjet printer. You're not likely to run into this as a problem, but be aware that Caslon, Garamond and Palatino are more robust than Times.
Line spacing can almost always benefit from a bit of opening up compared to what Word calls "Single" spacing. Use the "At Least" setting at 125%-130% of the point size (e.g., 15 to 16 pt for 12 pt text).
Use generous margins. Count the characters in a typical line of text; it shouldn't be more than 60-70 for extended technical reading, so adjust your margins accordingly. Part of your margin can be a left indent in your body text style. You can then "outdent" bolded text to make an easily-identified section start.
The best point size to use depends on the width of the lines and the nature of the typeface itself. 12 pt is a safe, especially if your readers are in the over-40 crowd. Palatino and its siblings, such as "Book Antiqua," work well at 10 or 11 pt. If you will print on an inkjet, definitely stick to larger point sizes. On a laser printer it's less critical, because toner doesn't spread the way ink does.
Keep your heading point size within 4 points of your text. 18 point headings tend to be a bit much, except for a document title. 16, or even 14, is plenty. Subheads should be at most one point larger than text. Use Bold or Italic to set them apart.
I hope this is helpful. I've tried to limit all of this to what you're likely to have on your computer already, rather than how I might answer a professional designer.