Re: Changing definition of "Large text" to use px rather than pt

Hi Gregg,

On 26 Apr 2016, at 2:42, Gregg Vanderheiden wrote:

> Notes are NOT normative.
> You are correct
>
> but in definitions…  hmmmm..
>
> pts are defined in inches — so they are an absolute number.

They are not in CSS. In CSS they are defined in px (1pt = 1.333px). 
There is no way for an author to ensure that an element or a specific 
font is a specific physical size. See my tests here: 
https://github.com/w3c/wcag/issues/181#issuecomment-214661286

Best, Eric

>
> pixels are not — or do you have some absolute definition of px 
> meaning a fraction of an inch (or mm)?
>
> gregg
>
>> On Apr 25, 2016, at 5:34 PM, James Nurthen <james.nurthen@oracle.com> 
>> wrote:
>>
>> Gregg,
>> Are the Notes normative too? I seem to recall that Notes are not 
>> normative in W3C specs and as such we could add a note (to accompany 
>> the 5 other notes) following the definition of large scale (text)  to 
>> clarify what 14pt and 18pt are equivalent to in px.
>>
>> This is important to solve. I had to answer this question twice this 
>> week from developers who couldn't understand why the contrast checker 
>> was returning an error for text that they thought was "large" (but 
>> was actually only 14px bold and hence was not large)
>>
>> Regards,
>> James
>>
>> On 4/25/2016 3:24 PM, Gregg Vanderheiden wrote:
>>> I’m not sure what you are referring to by "Changing definition of 
>>> "Large text" to use px rather than pt"
>>>
>>> Definitions in WCAG are normative.    They cannot be changed without 
>>> changing the standard.
>>>
>>> We can provide an advisory - but we can’t change the definition.
>>>
>>> If we are defining it differently in an extension - then that too 
>>> seems to are problematical
>>>
>>> If we are creating a  NEW version of WCAG  - the we could change it 
>>> — but there will be some confusion.
>>>
>>> Why is it needed?
>>>
>>>
>>> gregg
>>>
>>>> On Apr 25, 2016, at 4:54 PM, Patrick H. Lauke 
>>>> <redux@splintered.co.uk <mailto:redux@splintered.co.uk>> wrote:
>>>>
>>>> On 25/04/2016 22:41, ALAN SMITH wrote:
>>>>> Just a quick thought.
>>>>>
>>>>> I know many companies are designing for responsive design with 
>>>>> break
>>>>> points - as they call them - for several specific device screen 
>>>>> sizes.
>>>>
>>>> Clarification: screen sizes defined in CSS units (mostly pixels and 
>>>> ems), not physical dimensions (as there is no way to write a media 
>>>> query breakpoint in physical sizes). Which loops us right back to 
>>>> the start of the whole discussion.
>>>>
>>>>> Would there be any value in mentioning some common screen sizes in 
>>>>> any
>>>>> technical write up for this?
>>>>
>>>> If you were thinking along the lines of "typical sizes are X, Y, Z, 
>>>> and for those sizes your best font sizes are A, B, C" then there's 
>>>> possibly little value here, as the typical screen sizes bear no 
>>>> relation to the actual physical dimensions of screens, so again 
>>>> you'd be back at square one and not actually defining anything 
>>>> substantial, unfortunately.
>>>>
>>>> I think the one universal piece of advice when it comes to font 
>>>> sizing would be (from a readability point of view): don't make your 
>>>> base font size smaller than 1rem / the default UA base font size, 
>>>> and ensure that your viewport (for mobile/tablet devices) is set to 
>>>> the device/UA's ideal viewport (using width=device-width), as that 
>>>> should guarantee a font size that the device manufacturer/UA 
>>>> developer deems to be readable.
>>>>
>>>> P
>>>> -- 
>>>> Patrick H. Lauke
>>>>
>>>> www.splintered.co.uk <http://www.splintered.co.uk/> | 
>>>> https://github.com/patrickhlauke <https://github.com/patrickhlauke>
>>>> http://flickr.com/photos/redux/ <http://flickr.com/photos/redux/> | 
>>>> http://redux.deviantart.com <http://redux.deviantart.com/>
>>>> twitter: @patrick\_h\_lauke | skype: patrick\_h\_lauke
>>>>
>>>
>>
>> -- 
>> Regards, James
>> <oracle\_sig\_logo.gif> <http://www.oracle.com/>
>> James Nurthen | Principal Engineer, Accessibility
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--

Eric Eggert
Web Accessibility Specialist
Web Accessibility Initiative (WAI) at World Wide Web Consortium (W3C)

Received on Tuesday, 26 April 2016 08:10:38 UTC