Clear Print Guidelines from RNIB
Good standards of print legibility help all readers,
but for many people with a visual impairment the issue is crucial
to whether they read or not. It is important to recognise that
blind and partially-sighted people have different eye conditions
and what they see can greatly differ. It is therefore impossible
to devise a "print standard" which will meet all needs.
These guidelines simply aim to describe a few inexpensive, commonsense
steps which can easily be taken.
An important factor affecting print legibility is
the contrast between the type and the paper on which it is printed
(or photocopied). Contrast is affected by paper colour, printing
inks and type size and weight, all of which are considered below.
Without doubt publishers can best help blind and partially-sighted
people by paying attention to this very simple aspect of print
Black type on white or yellow paper gives a very
good contrast. If you wish to use paper in other colours, or to
print text on top of tints, the background colours selected must
be very pale. Dark background colours should always be avoided
as they rarely provide adequate contrast, especially if the type
Printing ink, if not black, should be as dark as
possiblefor example greens, blues, reds or browns can be
acceptable if dark ink is used and the background is very pale.
Never use yellow printing inks; they are as good as invisible.
Avoid pale colours on coloured backgroundsfor example grey
on blue. Do not be tempted to run type across a photograph or
illustration. This limits the contrast and confuses the eye.
In general it is easier to read black text on white
paper than white on black. White type on black paper is acceptable,
provided that the typeface, size and weight are suitable. Avoid
reversing out small type sizes and light faces because these tend
to fill in with ink and tend to become indistinct. Some blind
and partially-sighted people prefer reversed-out type if the size
and weight are adequate.
4. TYPE SIZE
Publishers should bear in mind that size can significantly
improve legibility. For the general reader type sizes between
8pt-10pt (this means that the height of a letter x is around 1
mm-1.5mm) are frequently used. These print sizes are not legible
to the majority of blind and partially-sighted people. RNIB's
own aim is to produce documents intended for general readers using
12pt (to give an x height of approximately 2mm). This is the "clear
print standard" to which we believe others should also aspire.
RNIB's research has shown that a significant proportion
of blind and partially-sighted people can read large print. The
type size commonly used in large print books is 14pt (giving an
x height of around 2.5mm). RNIB recommends this as the minimum
print size for material intended for blind and partially-sighted
However, RNIB requires 16pt when producing information
for blind and partially-sighted large print readers. RNIB's research
showed that the majority of blind and partially-sighted people
can read print of this size. There appear to be no advantages
in enlarging type above, say, 20pt, though larger sizes may be
necessary for headings.
5. TYPE WEIGHT
This is almost as important as the size in determining
legibility. Light typefaces should be avoided, especially in smaller
sizes. Blind and partially-sighted people may need medium or bold
type weights; even "regular" weights may provide inadequate
contrast between the type and the background.
Most typefaces in common use in books and newspapers
are legible and the choice of typeface is less important than
contrast, size, weight, and the way in which characters are spaced.
Typefaces to avoid are the obviously bizarre or indistinct ones.
If you print documents with numbers in them, for
example, bank statements, accounts or tables it is important to
ensure the numerals are as distinct as possible. Blind and partially-sighted
people can easily misread 3, 5 and 8 in some faces, and even 0
Stick to even word spacing. Do not stretch lines
of type or, worse, single words, to fit your line length. RNIB
prefers to use unjustified right hand margins; it is felt that
this is helpful to blind and partially-sighted people. Leave reasonable
space between lines of type: this text is set 13/15 point, that
is it has additional space between lines of two points.
8. LINE LENGTH
This should ideally be in the range of 50-65 characters.
Blind and partially-sighted people many prefer even shorter lines
than this. Avoid splitting words at the ends of lines.
Print on Glossy paper (art paper) can be difficult
to read, especially if your sight is impaired, because it reflects
too much light. Very thin, semi-transparent papers can also cause
problems because text can show through from the reverse.
10. CAPITAL LETTERS
These are harder to read than lower case letters.
Although a word or two in capitals may present no serious difficulties,
capitals should be avoided for continuous text.
11. DESIGN AND
This is very important as many readers are easily
daunted by a page of close-set type. Leave space between paragraphs.
Don't cram the page. Layouts should be simple and clear. It helps
to provide good "navigational" aids for the readerfor
example a contents list, clearly differentiated headings, rules
to separate un-related sectionsanything which makes the
layout easy to follow. RNIB prefer to avoid fitting text round
illustrations (which results in different line lengths). It is
also worth noting that, on forms, blind and partially-sighted
people often need generous space to fill in details that have
to be hand-written; their writing tends to be larger than average.
If you are setting text in double columns, make
sure the margin between columns clearly separates the two columns.
If space is limited, use a vertical rule to separate columns.
12. FUTURE RESEARCH
RNIB is planning to undertake further research into
print legibility, these guidelines are therefore subject to review.
Please contact RNIB for further advice on the production
of specific material.