Currently, we recommend users of FontLab Studio 5 and TypeTool 3 consider issues before they upgrade to macOS 10.13 “High Sierra.”

See our blog post for latest details and workarounds!


  • You are on macOS 10.13 High Sierra running FontLab Studio 5.1.5 or TypeTool
  • In the Font Window, copy/paste of glyphs and Append Glyph no longer work
  • If you are working with Multiple Master fonts (only) in FontLab Studio, copy/paste of glyphs or glyph elements in a Glyph Window only pastes one master, “flattening” the MM data.


See our blog post for latest details and workarounds!


With macOS 10.13 Apple has made major changes to how the clipboard works.

We do not currently have any ETA on a true fix, nor any solution for MM font editing. However, this is a decent workaround for the first problem:

To copy one or more glyphs in the Font Window:

  1. select the cell(s)
  2. click and drag the cell(s) to their destination, but do not let go of the mouse button
  3. Now press the Command key, and keep it pressed while you let go of the button

This works within a Font Window, or between two Font Windows.

You can let go in any empty slot. If no empty slot is available, let go in an occupied slot. You will get a dialog asking if you want to replace the glyph(s). If you say “no,” then the glyph(s) will be appended to the font instead.