Fonts: screen vs paper

Question

One thing I keep reading, especially in discussions about fonts for the Kindle, is that some fonts were designed for print but that nowadays designing fonts for onscreen use should be a consideration, and diffferent fonts should be used.

Aren't they both exactly the same thing; the decoration of a 2d surface which either reflects (in the case of the kindle) or emits (in the case of a phone screen or monitor) glyphs representing letters, numbers and punctuation?

Is it simply a resolution issue? Would people not have this issue if the DPI of the device was, say, 100,000 DPI rather than a couple of hundred?

Answer 1

Is it simply a resolution issue?

Yes.

And we're almost to the point where that issue is gone. Kindles, iPhones, iPads, all of the high-retina and e-paper devices now have resolutions that are nearly on par with paper so the issues that we had in the past due to the limited number of pixels we had at our disposal for each glyph are significantly lessened.

Answer 2

Screen and print really area different mediums--not just the "the decoration of a 2d surface". Here are a few differences:

• Users can change type on a screen. They can override the designer's size, choice of typeface, even color. Type design on a screen needs to be able to account for this.
• Print and screen use different color modules (CYMK vs RGB)
• Most devices don't have a truly black screen. They often reflect light to some degree.
• DPI for print and PPI for screens are not the same thing.
• A screen is (usually) backlit. Reading on a computer screen is a bit light staring at a lightbulb at times, which causes fatigue when reading.
• No screen is the same. A web page might be viewed on completely different devices, like a 22" desktop monitor or a 3.5" phone. Typography in the digital world needs to accomodate both.
• Except in cases of ereaders, there is more stuff on a screen--other content on the web page, email notifications, xeyes, and who knows what else

These differences mean that (in general) screen typography needs to favor legibility. Not only does the average computer screen have less resolution to work with compared to print, there are distractions that draw your eyes to different places, variability in user settings (the same text on a website might be "big" on my laptop but "small" on my phone), variability in available fonts, etc. There's also the general fatigue of using a device. Fonts on screen need to be simpiler and easy to understand at a glance.

This is why sans-serif fonts with big X-heights and an open feel like Open Sans dominate the web. They are simplier and work in various sizes without much strain on the reader. They are also easier to scan and easier to find your place when you look away (oh look, a funny cat picture!).

Answer 3

When fonts are meant to be printed on paper, a type designer has to take into account how the printing plates, the ink, and the paper will interact to produce a character. This means they might have to make different cuts for different sizes, or add ink traps so the ink doesn't clog up small spaces in the letters.

When fonts are meant to be viewed on screen, a type designer has to take into account how the type rendering engine (usually built into the operating system) and the screen will interact to produce a character. This means they might have to hint the fonts so they display properly at different sizes, or construct them based on a pixel grid.

Sure, things are evened out a lot when we're talking about a high resolution display, but there will always be differences between how a font behaves on screen and on print, and if you're designing exclusively or primarily for one of these mediums, as a type designer you will do things differently.