Fussiness under the baseline

PabloImpallari

I'm cant find a solution to this little problem:


If you look closely, will see that at 14 and 16pts there seems to be grayscale pixels under the /n serifs. How can I remove it, so it looks like the ones at 15, 17 and 18pts? (Firefox/Mac)

The blue lines are already in place, like this:

However, the problem remains.
I spend all day experimenting, hinting, un-hinting, tweaking blue values, looking at pixels, etc... and wasn't able to find a solution. Nothing seems to make any difference.

The greyscale pixels below the /o are OK, but not the ones below the /n, /i, /l, etc...

Ralf H

Nothing seems to make any difference.

Well, that's because the Mac doesn't use the hinting settings.

Rainer Erich Scheichelbauer

Changing your hhea values may have an impact on it. I guess OS X does not gridsnap cubic curves. If you re-install the font in the system, make sure you empty caches and restart first, or rename the font every time.

But seriously, why bother? This is only an issue if you scale a screenshot like this.

PabloImpallari

@Ralph: I have read somewhere (don't remember right now) that while the mac ignores the hinting, it does uses the blue values. But now, after testing, I'm not sure the blue values have any impact.

@Mekka: Thanks, I will play around and report back if I found a solution.
It's an issue for me, type looks much more crisp at 14px whiteout those pixels under the straight stems.

PabloImpallari

Two days, a lot of cigarettes and coffee later... finally found a solution!

@Ralph:
Mac may ignore the hinting, but renders quality can still be controlled!
The fussiness/sharpness of the text, seems to be related to the Vertical Metrics, as Mekkablue suggested, and the vertical BBox.

@Mekka: Playing around with the vertical metrics was the solution! Also, a little bit of blue values tweaking.

This is how awesome it looks now (compare to the image in the first post):


It makes all the difference in text sizes.

Now it renders as good as the Webtype RE series, or the new H&FJ SmartScreen fonts.
And maybe even better at 10 and 11px (Keep in mind that I only fixed the vertical metrics, there are still room to tweak the horizontal metrics and stem widths).

Rainer Erich Scheichelbauer

What did you do with the BlueValues? Before/after?

PabloImpallari

Tested hundreds of combinations :), until it worked out Ok.
I will find a formula soon... I will also upload the source code for this font (as I do with all my other fonts) in my website projects section, so you will be able to see for yourself.

As a side effect: It also improved the fussiness at the top of the x-height, not only at the baseline.