I have a question. How to set a modify permission into the TTF I made, so that users who receives my font products can only install them but cannot modify the type’s glyphs and the information of font.
In File > Font Info > Font, add a custom parameter called fsType. Read here what the values mean: OS/2 - OS/2 and Windows metrics table (OpenType 1.9) - Typography | Microsoft Learn
Please understand that whatever you set here will not technically prevent anyone from modifying your font.
From the documentation:
fsType A list of bit numbers indicating the embedding type. The bit numbers are listed in the OpenType OS/2 specification. Corresponds to the OpenType OS/2 table fsType field. ‘Type flags. Indicates font embedding licensing rights for the font. Embeddable fonts may be stored in a document. When a document with embedded fonts is opened on a system that does not have the font installed (the remote system), the embedded font may be loaded for temporary (and in some cases, permanent) use on that system by an embedding-aware application. Embedding licensing rights are granted by the vendor of the font. The OpenType Font Embedding DLL Specification and DLL release notes describe the APIs used to implement support for OpenType font embedding and loading. Applications that implement support for font embedding, either through use of the Font Embedding DLL or through other means, must not embed fonts which are not licensed to permit embedding. Further, applications loading embedded fonts for temporary use (see Preview & Print and Editable embedding below) must delete the fonts when the document containing the embedded font is closed.’ You can set fsType to one of these five states:
• Installable: ‘Fonts with this setting indicate that they may be embedded and permanently installed on the remote system by an application. The user of the remote system acquires the identical rights, obligations and licenses for that font as the original purchaser of the font, and is subject to the same end-user license agreement, copyright, design patent, and/or trademark as was the original purchaser.’
• Forbidden: ‘Restricted License embedding: Fonts that have only this bit set must not be modified, embedded or exchanged in any manner without first obtaining permission of the legal owner. Caution: For Restricted License embedding to take effect, it must be the only level of embedding selected.’
• Editable: ‘When this bit is set, the font may be embedded but must only be installed temporarily on other systems. In contrast to Preview & Print fonts, documents containing Editable fonts may be opened for reading, editing is permitted, and changes may be saved.’
• Preview & Print: ‘When this bit is set, the font may be embedded, and temporarily loaded on the remote system. Documents containing Preview & Print fonts must be opened “read-only;” no edits can be applied to the document.’
• Subsetting forbidden: ‘When this bit is set, the font may not be subsetted prior to embedding. Other embedding restrictions also apply.’
thank you！
I just did not make my question clear. I want users cannot modify my fonts’ glyphs, information or export fonts through Glyphs and Fontlab or another making-type softwares. It’s not just about fsTYPE. Because I just set up the state Preview and Print according to the handbook , but the exported TTF can still be modified and re-exported through Glyphsapp.
thank you！
I just did not make my question clear. I want users cannot modify my fonts’ glyphs, information or export fonts through Glyphs and Fontlab or another making-type softwares. It’s not just about fsTYPE. Because I just set up the state Preview and Print according to the handbook , but the exported TTF can still be modified and re-exported through Glyphsapp.
There is no way to prevent modifications.