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Re: CSS3 font-weight, OFF OS2.usWeightClass, and weights which are not a multiple of 100.

From: Tal Leming <tal@typesupply.com>
Date: Wed, 9 Feb 2011 12:08:38 -0500
Cc: www-font@w3.org, www-svg@w3.org
Message-Id: <F849E5BA-AF61-4B6B-8323-C3FEDC639307@typesupply.com>
To: Chris Lilley <chris@w3.org>
On Feb 9, 2011, at 9:20 AM, Chris Lilley wrote:

> a) are the above assumptions correct?

I can't answer the CSS questions, but I can comment on this:

> I have seen fonts with weights like 250 etc so I conclude that in OFF, OS2.usWeightClass is a continuous range of cardinal numbers.

This has been done to work around software bugs and to give a better user experience. The best documentation of the bug workarounds is here:


On the user experience side, the Adobe Creative Suite uses the weight value for menu sorting. So, we end up reworking the 250-1000 range to make the sorting better. I've seen, and made, fonts with ranges like 250, 267, 283, 300, 400, 450, 500, 700, 900.

Furthermore, there are families with more than 9 weights. And, sometimes after a family has been released we get requests for new weights between existing weights. That requires even more value slicing.

Received on Wednesday, 9 February 2011 17:11:00 UTC

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