I’m not familiar with Fontographer, but this looks like you have some autohinting applied on TTF generation. Is it possible? For a display font like that, I think you would be better set without any hinting at all.

Hi, Grzegorz!

Yes, there was some autohinting, but... I manually removed all the hints and it's still the same. Now even the system's preview compresses the upper part of the glyphs. The OTF is perfect, though.

OTF

TTF

I'd be inclined to suspect a problem in the auto-conversion of PS to TT outlines.

You might want to try explicitly convert the outlines to TT yourself within the program (without generating the font) and then double-check the glyphs. (I'm not familiar with Fontographer, but I assume it has a way for you to do that, as FL does.)

Maybe your OTF Postscript font contains points with non integer coordinates (a perfect hexagon would have some vertices with irrational coordinates). Coordinates in truetype must be integers and the difference may simply be due to rounding.

Definitely there are vertical hints.

@jonhych > Yes, there was autohinting in the whole font. I removed all the hints manually but I haven't uploaded the newest version yet. Nevertheless, the two last screencaptures show the OTF and the TTF without the hints.

@altsan > I'll check if there's a way to do what you suggested in Fontographer.

@Michel Boyer > If thats's the problem, the TTF will never look as good as the OTF?

(Just for you all to know, the problem happens whether I generate the TTF directly or converting the OTF to TTF.)

I'll check your suggestions and post later.

Thank you all!

If thats's the problem, the TTF will never look as good as the OTF?

I just downloaded Beetype-Filled.otf from your site and looked with ttx and that's not the problem. On the other hand, postscript fonts allow cubic bezier curves and truetype only quadratic. Since all your "curves" are straight lines, i.e. of degree 1, I don't see how the problem could come from there either.

I had a brief look at the .ttf font using OTM and IMHO what you see is normal rounding. Using our own auto-hinter and TTFA did basically not lead to much better results, so I don’t think Fontographer is to blame. If you want to prevent the distortion at smaller point sizes, this requires some manual hinting, I reckon.
 

I could be wrong, though…
 

@Michel Boyer > Thanks for taking a closer look ot the font.

@blokland > I'll try some manual hinting and let you know if that fixes the problem. Thanks.