WebAIM - Web Accessibility In Mind

E-mail List Archives

Color Contrast

for

From: David Ashleydale
Date: Jun 3, 2009 12:30PM

Thanks for your help with this. The main problem I was running into was that
our designers often use Photoshop for making prototypes and specs. When I
told them about the 18 point and 14 point requirements, they responded that
points and pixels are the same. I didn't think this was true, so I gave it a
try. When I created a new image, it defaulted to 72 ppi and sure enough 14
pt and 14 px were the same. However, when I changed it to 96 ppi, 14 pt was
closer to 19 px, which is what I had observed in HTML.

We definitely use relative units for HTML, so I tried the 1.2 em and 1.5 em
and that also gave the same result as 19 px and 24 px. However, we also have
some marketing assets on our site that are images with text in them. The
designers need to know the non-relative units so that they can create these
assets with enough contrast (Photoshop doesn't have font size units in em or
% - just pixels, points and mm). So I will tell them to use 24 px and 19 px
bold as the "large" font size when using the Color Contrast Checker.

P.S. We also try not to use text in images if possible, but the font family
for our brand is not a standard font that is included with most computers.

Thanks,
David