Hinting Preview

Experimental. macOS never executes hint programs. Core Text draws your outlines and ignores the hints entirely, so a font can look perfect in every Mac app and still come out different in Acrobat, on a printer, or on a Windows screen, the environments that do run the programs. Hinting Preview renders the proof through FreeType with hints executed, so you can check what the rest of the world sees without leaving your Mac.

Hold H to blink between your drawings and the hinted rendering; G and J step through the presets

Using it

  • Tap H over any proof to flip into the hinted view. Tap again to come back.
  • Hold H to peek and release to return, a spring-loaded comparison. Because the hinted view keeps the exact same layout, scroll, and zoom, the only pixels that change are the ones the hints moved, and your eye catches them immediately.
  • G and J step through the dpi presets while the hinted view is showing (G coarser, J finer).
  • The first use renders in the background for a moment; after that, switching is instant.
  • Also in the View menu: Turn On/Off Hinting Preview (Option-Command-H).

The presets

Each preset shows what a reader would actually perceive in a real scenario:

PresetSimulatesShows
72 dpiOlder office monitorHinted grayscale rasterization
96 dpiTypical Windows desktopHinted grayscale rasterization
144 dpiHigh-resolution laptop screenHinted grayscale rasterization
300 dpiOffice laser printerHinted outlines
600 dpiCommercial digital printHinted outlines
1200 dpiOffset plates, imagesetterHinted outlines

The screen presets rasterize with hints executed, close to how Windows draws text, which is the environment most manual hinting is authored for. The print presets skip the pixels (nobody can resolve a 600 dpi dot) and show the grid-fitted outlines: your drawings as the hint programs reshaped them, which is exactly the geometry Acrobat hands a RIP.

“Show pixels for print presets” in the View menu switches the print presets to raw bi-level rasterization. Its one unique use is catching hairlines that drop out at a single pixel of width.

What it is and isn’t

  • TrueType hints run through the full classic interpreter; PostScript/CFF hints run through the Adobe-contributed engine, the same lineage as Acrobat’s rasterizer. We call this hint-honoring rasterization. It is not a pixel-exact simulation of any single product.
  • The preview is a working mode. Exported PDFs are always vector and never contain rasterized text.
  • Fonts inside TTC collections, vertical text runs, and color fonts currently stay in the normal vector rendering.

Credits

Hinting Preview is built on the FreeType library. Portions of this software are copyright © 2025 The FreeType Project (www.freetype.org). All rights reserved.