How many times have you re-focused your eyes, squinting to make out the charges on a restaurant check, or to read the confirmation number on a credit card? It happens to me all the time. My favorite example is my Costco card (Figure 1). Imagine having to transcribe that number onto an online order. If you look extremely close, you will notice that the numbers 6, 8, 5 and 3 in the typeface chosen look similar, making them hard to distinguish. Ironically, if you look at the numbers embossed on a credit card, you’ll notice that they are highly differentiated.

Clients are having the same problems with many statements. Considering that only mathematicians and programmers have a natural knack for reading arrays of numbers, most people need as much visual differentiation as possible (Figure 2). When clients can’t decipher the details, their minds start questioning both the data presented and the professionalism of the organization involved.

With over 140,000 commercially available typefaces, I don’t know why designers continue to choose typefaces with numbers that can be easily misinterpreted by
consumers. I personally believe that many typefaces
are never tested for readability within tables.

The newer composition tools allow the use of virtually any commercial typeface. As a result, most organizations are setting their client statements in the typeface specified in their corporate style-guide. Although this creates a document consistent with other corporate collateral, it causes problems if the numbers were not designed for tabular presentation.  As a result, the newly designed statement may look very attractive, but the detailed financial information becomes hard to decipher.

Type designers develop their typefaces[1] based upon the targeted media and readership. Unfortunately, the face can end up being used for applications that are completely foreign to (and many case wrong for) the face’s purpose. For example, Stanley Morison designed Times New Roman for printing newspapers, but it is the default face in most computer applications. Adrian Frutiger designed his Frutiger typeface for signage at the Charles De Gaulle International Airport in Paris. It has become one of the most (over) used faces on customer statements today.

I personally helped develop a typeface for shelf labels in supermarkets in the 1980s. The characters had to be narrow and the numbers very distinguishable because most people read labels at a severe angle.  Although we mimicked the corporate typeface, the primary objective was to have a 1/2 inch set of numbers that you could read from six feet away at a 60 - 70° angle (the bottom shelf).

We develop typefaces based on function. If the face was never intended for the function required, use one that looks similar and fits the requirement. With all those typefaces available, one will be appropriate.

Picking a numeric typeface

1. Remember, you don’t have to use the same typeface for numbers as you use for the description or titles.

2. Choose a numbers typeface with (Figure 3):

1. all numbers having the same width                                 
2. ascender on the 6 pointing up  
(at a 2-oclock angle)
3. descender on the 9 point down
(at a 7-oclock angle)

4. lower circle of the 8 looking different
than the 6
5. upper circle of the 8 looking different than the 9
6. descender on the 5 points up at (at a 10-oclock angle)
7. 1 has a serif at the top that points slightly down
8. ascender and descender on the 3 point out (not at each other)
9. 7 has a dominant stroke at the top

3. Choose a typeface that mimics the corporate face, e.g. if your
corporate face is Frutiger, find a number typeface that is
similar like Avenir (also designed by Adrian Frutiger)
shown in Figure 4. I have included a table with numeric
examples of the most popular corporate typefaces
(Figure 6).

4. Avoid ‘old-style’ or ‘expert’ numbers within tables (Figure 5)
unless you leave lots of space between the lines. Testing has
shown that a column of numbers in an old-style face
is difficult to read [2] 

5. Use proportional, ‘old-style’ numbers within text blocks in the statement, if available.

6. Test your table layout in a quantifiable manor. Don’t ask the focus group how they like the table layout. Ask them to read the numbers and answer a question based on what they read.

You make your client statement readable and comprehensible by paying attention to minute details. Choosing a separate typeface for the numbers in the tables can help the client digest the information in the statement more quickly and thoroughly. This will result in fewer service calls and a higher level of loyalty.

[1] One of the industry names for a style of characters. They are also referred to as fonts or type styles.

[2] Tinker, M.A. ‘Legibility of Mathematical Tables’ Journal of Applied Psychology, 44, September 1960, pp83-87