Knowledge Base - Rehinting a Font
#03722: Rehinting a font Issue Font displays poorly on screen at small point sizes. Reason Many commercial TrueType fonts for Windows use custom technology (referred to as delta hints) to improve the quality of the screen font. The TrueType instructions do most of the work of adjusting a character's outline to the screen's grid, but sometimes the outlines fall in such a way that filling the outline would not turn on the desired pixel. Delta hints are a way of making a subpixel adjustment to a point such that the enclosed pixels get turned on or off as desired. These delta hints cannot be automatically generated they are manually applied to the outline by software engineers. The results of good delta hinting can be seen by taking a close look at Arial, CourierNew, and TimesNewRoman in Windows. When Fontographer reads a TrueType font it is unable to retain the delta hints. If Fontographer were to retain the table containing the delta hints, any modifications to any of the glyphs would void the outline sensitive delta hints. Solution Use Fontographer's Hint Parameter features to recalculate the font's outlines, as detailed in the steps below. Note: A normalized em square is always 1000 in accordance with the Adobe Type 1 specifications for Postscript fonts and 2048 (or a multiple of 1024) for TrueType fonts. Rehinting a font in Fontographer 1. Choose Edit > Select All to select all characters. 2. Choose Hints > Vertical Alignment Zones > Recompute. 3. Click OK after the recompute process finishes. 4. Choose Hints > Hint Parameters > Recalc . If Recalc is disabled,then go to Step 6. 5. Click OK after the recalculation process finishes. 6. Choose Hints > Autohint to turn Autohint off and then immediately turn Autohint back on. Non-roman characters The manual points out that Fontographer averages the stem widths of the characters in order to calculate the hints. Dingbats, Wingding or logo artwork will not have Roman character stems so it is best to rehint the font without these types of characters present in the font. Put them in a temporary work font and paste them back in with the Roman characters after the rehinting process. Also, if the artwork in the font is displaying or printing strangely then turn off hinting before generating the font or generate it as a Type 3 font. Additional Information If the above steps don't improve the character, then the poor display of a font's characters may occur because the font was manually hinted.
Created : 2013-10-28 19:29:41, Last Modified : 2013-10-28 19:29:41