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可以参考 ISO/IEC GUIDE 37---Instructions for use of products by consumers.里面的7.2章节:
7.2 Legibility of text
7.2.1 All instructions should be easily visible and legible (with normal eyesight) from the distance at which users need to read them. Elements contributing to legibility include the viewing distance and angle, the style, size and colour of text font, the colour of the background and the brightness contrast between them.
7.2.2 The location of on-product instructions and the angle between their surface and the vertical plane should be such that they can be easily read and understood by users from their position(s) during use of the product.
NOTE For any information that needs to be legible from a greater distance, the product standard might need to specify the minimum viewing distance.
7.2.3 Instructions on packaging should be visible and legible in the package’s upright position. Where the visible surface area of the product or packaging available for text is necessarily very restricted, the product standard should specify minimum font sizes and brightness contrast.
7.2.4 Unless national legislation or standards make specific requirements for legibility (e.g. the relation
between type size and reading distance), the rules below should be regarded as the minimum acceptable as good practice.
a) Critical on-product text (e.g. control markings) should be expected to be as clear and as large as
practicable to be legible (at distances up to 1 m) by as high a proportion as possible of older users with degenerating eyesight. This is likely to require a 14- or 16-point font with an “x-height” for lower-case letters of 4 mm or 5 mm.
b) In contrast, where space is limited by product size (e.g. in containers of less than 10 ml in capacity), an absolute minimum font size of 6 points may be tolerated, but only for continuous text in a high resolution plain black font on a bright (but not high-gloss) white background (with headings and warning phrases in a minimum font size of 8 points and a minimum “x-height” of 1,5 mm).
c) Wherever space allows, continuous text in instructions on hand-held products, labels, packaging or
multiple-folded instruction sheets should have a font of 9 points or larger. 12 points (or 3,2 mm “x-height”) is the desired minimum for critical safety limits (e.g. minimum user age, expiry date, maximum load) or warning phrases (unless also presented by a standardized symbol).
d) Continuous text of instructions in accompanying printed documents (e.g. single-folded leaflets and
manuals) or in electronic displays should have a minimum font size of 10 points if in dark or strong colour against a plain light background. White text on a dark background requires a font size of at least 12 points to be effective.
e) In any document, headings, critical safety limits, key warning phrases and key details that the user needs to consult frequently should use a different font style, larger font size, or other means of making them conspicuous. A minimum font size of 12 points (or an “x-height” of 3,2 mm) should be used. If there is any doubt as to whether particular instructions are related primarily to safety or to fitness for purpose, considerations dealing with safety should be given precedence.
EXAMPLE “Heading”, “critical safety limit”, “KEY WARNING PHRASE”.
7.2.5 A substantial number of older consumers and consumers with deteriorating eyesight have difficulty in reading the print on many packages and leaflets supplied with products. Whenever practical, suppliers should offer them options of access to the information in alternative media (preferably audio and large print).
7.2.6 As a minimum, whenever the instructions supplied with a product present any of the text in a font size smaller than 10 points, or the legibility of the text is decreased by other factors (such as poor contrast), the supplier should ensure that a larger print version (with a minimum font size of 12 points) is readily available to consumers upon request (e.g. as a download from their website and/or a leaflet available at the point of sale). This source should be indicated on the product/packaging/instruction leaflet supplied at purchase in a minimum font size of 10 points.
7.2.7 For other alphabets, the selection of lettering type and size should meet a comparable degree of legibility to that indicated above.
7.2.8 The minimum sizes recommended here for lettering assume an optimal brightness contrast (the
difference between the percentage of light reflected from the background and the percentage of light reflected from the print). The contrast should normally be at least 70 %. Good quality black print on white paper provides a contrast of about 80 %.
7.2.9 Many older people, or young people with colour vision disabilities, perceive inadequate contrast in red/green combinations, subtle colours or pastel shades, patterned backgrounds or insufficiently opaque paper printed on both sides; consequently, instructional text should not be presented in these formats. Instructions should never be printed on transparent material.
7.2.10 If instructions appear within the material of the product itself, e.g. in the form of engraved or
embossed lettering, figures or symbols on metal, glass or plastic, the advantages of such methods
(e.g. durability, reduction of numbers of separate parts) should be weighed against the disadvantages (e.g. reduced contrast and consequent reduced legibility compared with that obtained with good printing). (See also 7.3.) |
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