Serif vs Sans-Serif Type

An online freelance group of which I am a member has been sending emails back and forth regarding the relative legibility of serif vs. sans-serif type. I’ve been reading the email strings, but today I just had to weigh in.

Everyone has an opinion. And there are numerous studies on the subject. That said, these are my thoughts, based on 45 years’ in the business, doing everything from design to typesetting (on a dedicated typesetting machine, back before the Macintosh), to print brokering, to writing.

As with anything else in life, rules are meant to be broken. With type, it's important to do this with readability in mind.

The first rule of thumb is that serif type is easier to read in print (the serifs move the eye from one letterform to the next), and sans-serif type is easier to read on a computer screen. (Sans-serif fonts are easier to read than the more complex serif fonts on a grid composed of square pixels.)

That said, here are some things to consider:

1. The age of the viewer. As we age, our eyes don't change focus as easily or quickly.

2. The color of the type and the color of the background (the type relative to the page of a book or the background color of a computer screen). This pertains to the relative values of the type and background as much as, if not more than, the colors themselves.

3. The number of hues in the build of the color (made from either light on a computer screen or ink on a page). For instance, a serif typeface at a small size composed of magenta, cyan, and black ink may be hard to read in a serif face if the printing plates are out of register. (The eye is more forgiving of misalignment of the yellow plate.)

4. Bold type is harder to read than roman. Italic is harder to read than roman. Reversed type is harder to read than black type on a white background. The key is the amount of type. You can choose a serif face, reverse it out of black (keep the relative values in mind: more contrast is better), increase the type size slightly, and limit the number of words you reverse, and you'll be fine.

5. Line width makes a difference. (Shorter lines are more legible for both serif and sans-serif type).

6. The typeface and general category of serif type (sans serif as well) are important. We're more used to reading Old Style serif type with a slight slant in the letterforms and less dramatic changes in the width of the strokes. Then you have Transitional and Modern typefaces (with more contrast between thick and thin portions of the letterforms). I consider these harder to read than Old Style. Within these three classifications there are more serif typefaces than I can count. Choose a few, set some type, and ask a handful of people at the target age range what they think about the legibility of the type.

7. Leading makes a difference. If a paragraph is set with very little space between the lines, it will be hard to read. Spreading out the lines a little makes an illegible typeface much more readable.

So the short answer is that all rules of design can be broken if done with forethought and skill. Choosing a serif or sans-serif typeface for online reading or reading on paper is less relevant than how you use the other nuances of typesetting to improve legibility.

I don't have studies to back this up. I've read many studies over my 45 years' in publications. Most of what I've learned, I've learned from reading and observing (and trusting my eyes when either designing or analyzing graphic design).

"PUR" (Polyurethane Reactive) Glue Vs. Regular Hot-Melt Glue For Perfect-Bound Books

I’m brokering four books for a client at the moment, 5.5" x 8.5" books of fiction and poetry. Two are galleys, produced for reader review (75 copies) and two are final editions (1,500 or 2,000 copies). Only the final copies will have French flaps and a hinge score. They need to look spectacular because they will be sold at a premium to people who specifically want the tactile experience of the physical book: what it looks like, how it smells, and how it feels in their hands.

The galley proof books need to last for only a short while. They will most probably be marked up by the readers, who will suggest corrections before the final editions are released for printing. In contrast, the final editions should last a long, long time and tolerate repeated use.

All of this is relevant when you consider that books are physical objects with physical requirements. For instance, the glue has to hold the pages firmly in the binding. My fiancee and I spend a lot of time at the thrift store, where I always gravitate to the books (many of which are 30 years old). I can tell you that I’m not fond of broken book spines and pages that seem to want to fall out. Even if the thrift store books are inexpensive, I’d prefer they last another 30 years. All of this (quality of paper, quality of glue, binding skill) pertains to the physicality of the print book.

In this light, one of the printers bidding on my client’s four books noted that although I had requested PUR glue for binding, his company offered hot melt perfect-binding glue, and he had found that hot melt glue was perfectly fine. It held the pages firmly in the binding of the textbooks his printing company produced.

Keep in mind that years ago, based on someone else’s recommendation, I had started specifying PUR glue for all perfect-bound books because I had heard it lasted longer and was actually flexible when cured (i.e., cool and dry). This new printer, when pressed, and when I explained the use of the two final editions (i.e., a lot of use over a long period of time), said he actually agreed that PUR glue was better (and worth the extra cost and time) because it held onto the pages more securely over the life of the book.

Based on his recommendation, I just did some research. This is what I found, as noted on the www.3m.com website:

"Structural strength with hot melt speed
"Polyurethane reactive adhesives (PUR adhesives; also called reactive hot melts, reactive polyurethanes or RPU adhesives) are one-part formulations that combine the initial speed of a hot melt adhesive with the strength of a structural adhesive. The bond forms in two stages: when the adhesive cools back down and solidifies like a hot melt it reaches holding strength, then the moisture-curing reaction proceeds over the next 24-48 hours to reach final structural strength. These adhesives are resistant to temperature extremes and flexible to provide vibration and impact resistance.
"3M™ Scotch-Weld™ PUR Adhesives have a range of open times that can be adjusted to suit your process, and they have low to no Volatile Organic Compounds (VOCs). These adhesives bond well to metals, glass, ceramics, wood and some plastics such as polystyrene and polyacrylic. The combination of no-mix one-part application, rapid handling strength and high final strength makes PUR adhesives excellent candidates to help improve throughput and reduce processing time."

Strength and flexibility: both essential qualities of book-binding glue. So what does this mean for your print buying work?

If you’re producing books that are for immediate, short-term use, you may want to pay less and have your printer use traditional hot-melt glue. (My client’s galley books would fit in this category.) However, if you want the glue binding to actually strengthen over time and remain flexible, because you want the bound books to last a long time, take repeated use, and have fewer issues with ambient temperature conditions, you may want to specify PUR glue. Keep in mind that not all printers offer both hot-melt and PUR adhesives, so ask about PUR glue early in the process.

And just as an aside, both of these glues are liquefied at high temperature and then flow into the notched or ground edges of the folded book signatures. As the glue cools and cures, it grips the surface of the paper and holds it into the binding. The notches or grinding just provides more surface area for the glue to grip, strengthening the binding.

And regarding durability, that brings us right back to the beginning, with PUR glue being the more durable option. So the first question to ask yourself is, "How long does this perfect-bound book need to last?"

[Steven Waxman is a printing consultant. He teaches corporations how to save money buying printing, brokers printing services, and teaches prepress techniques. Steven has been in the printing industry for thirty-three years working as a writer, editor, print buyer, photographer, graphic designer, art director, and production manager.]