There is not much useful data on how to make text look as readable as possible on screen. I have found that for me it’s uncomfortable to read PDFs due to type, layout and strong black on white. The advice I get is simply to print the documents out, but that would defeat the purpose of my thesis, which includes the aspect of literature review and how to make it more effective not just to read and annotate, but to find annotations later and to cite from the literature.
“What’s the most readable font for the screen?” http://thenextweb.com/dd/2011/03/02/whats-the-most-readable-font-for-the-screen/ does not provide anything useful, it, as many other sites, say much is personal choice, other than pointing out that for non-retina screens sans-serif looks best but for retina displays that difference has been reduced.
“Type Sizes or Every Device” http://www.uxmatters.com/mt/archives/2015/09/type-sizes-for-every-device.php covers different displays quite well, but I’m only designing for computer screens for this project so it’s not brilliantly useful, other than pointing our the importance of contrast for legibility.
I have looked at applications as well, particularly Apple iBooks which have #f9f3e9 background colour and #5f3e24 as the font colour. This is what I started using for my own Author project, but it’s drifted through experimenting from that to #f5efdd for the background colour, which you can see is a bit less red. Notice also that in Author I use fully black text.
Screen Colours, Columns & Column Width
My poll on two screenshots on Facebook is here and in summary the preference is largely for a cream background but not too wide columns, which fits with my own preference and what I can find online, though a word processor view with a very narrow column wastes a lot of screen space so maybe we should add an option for setting the max width or maybe we should encourage the user to use non-full screen and go as narrow as they prefer.
I have measured newspapers and found that they have about 7 words per line. Additionally: “Anything from 45 to 75 characters is widely regarded as a satisfactory length of line for a single-column page set in a serifed text face in a text size. The 66-character line(counting both letters and spaces) is widely regarded as ideal. For multiple column work, a better average is 40 to 50 characters.” http://mikeyanderson.com/optimal_characters_per_line
Major Sites Survey
These sites all have white background (#fff) and differing colour text:
Quora: #333 on #fff
facebook: #141823 on #fff
twitter: #292f33 on #fff
linkedin: #333 on #fff
New York Times: #333 on #fff
From Quora I also read “High contrast color pairs, such as black and white, can create a sense of vibration on the screen and stress the eyes.” Jonah Model, Digital product designer, founder of Paper & Equator https://www.quora.com/What-is-the-best-font-color-for-text-on-a-white-background-screen which makes sense.
As a conclusion I’m sticking with the Author colours for now at least, the beige background in Read mode and light grey in Edit mode and we’ll change it if testing indicates we should.