Question about Isonorm 3098

It seems there are various versions of the typeface 'Isonorm' available. I personally have the Isonorm 3098 version... Can anybody tell me what the '3098' actually means? The different versions have additions like, 'g' 'sb' 'b', yet appear to be exactly the same, apart from a variation on the 'a' in some versions...

can anybody give me more info on the typeface... more out of curiosity than anything else..

Thanks. C.


Hi Charles,

Not sure if you'll find this given the age of the original post, but I came across it while searching for more Isonorm goodness three years on...

The '3098' refers to the International Organization for Standardization (ISO) standard for lettering in technical drawings (ISO 3098-1:1974) because the font adheres to the design standards set out therein. There's a whole classification system to this typeface and the various letters include V (vertical) or S (slanted, or italic) variations etc.

A and B sets were designed for use with either stencils or transfers (remember this is a font whose design predates common use of computers to create technical drawings for engineers and architects - back in university days I remember using some wonderful Rotring stencils made from transparent orange plastic for the 3098 font). CA and CB were designed for CAD software use. Another descriptive letter indicates the ratio of the height of the character to the width of the stroke used - I can't remember the letters these days but the two options for the ratio are 1/14 or 1/10. Depending on the country you're in, the standard is one or the other I recall (another aspect specified by country is the style of the lower case 'a' and whether or not the '7' has a bar across it). The entire standard specifies all sorts of sizes by reference to the letter height - ascender and descender heights, space between words (between 0.6h and 2h), leading (not less than 0.6h), etc. as well as a basic style guide (upper and lower case usage, no underlining of letters, decimal points sit on the base line and the like). Think of it as 'what happens to an art like typography when engineers get their sticky mitts on it' and you won't be disappointed!

In terms of the font family, you'll see only one letter specified and notice slight differences in the character sets between them (breaks in stencilled letters, etc.) which are driven by practical considerations for the intended implementation. When defining the sytle guide for a technical drawing though, you'd expect to see a full type specification to indicate character set, vertical or slant, height to stroke weight ratio, etc. for every style used.

Common use of the standard also indicates a typographic scale, i.e. 5mm for small print on diagrams, 10 for body text, 14 for headings and 20 for titles commonly. Yes, that's millimetres - this being a standard it defines absolute values, not point sizes for character height.

The combination of all these factors in the overall specification is intended to allow for maximum overall legibility, even when plans and other technical drawings have become slightly damaged (through repeated folding, general wear and tear on site, etc.) leading to the odd part of a letter being 'lost' in the process.

There are a number of type foundries producing versions of this font, but to your point of how similar they all are I guess a lot depends on how accurately the foundries have been able to recreate the original specifications.