Universal font change in all documents?

You are making a terrible assumption here, that the “old, outdated TT file set of Helvetica Neue” that you currently have installed and are using is really the exact same font as “the current OT family that Linotype offers.”

Ignoring all the wonderful advise offered by other contributors to this thread, you should be aware that just because the name Helvetica Neue is the same, you cannot assume that the font metrics and the encodings are the same.

Differences in metrics including set widths of particular characters and pair kerning tables may very well lead to different line and page breaks.

Differences in encodings between the old and new fonts may result in the wrong characters and/or the .notdef glyph (the box with the X in it) displaying and printing after you actually do the substitution.

You will need to go through your documents and look for these possible discrepancies!

          - Dov

It looks like a very interesting idea for making a script.

I wrote a quick & dirty script for changing fonts which should be used together with my new Batch processor.

Here I posted the script and before and after sample documents (ver. CC 2017).

In the future I'm going to make a more user friendly version so the user could prepare a list of the fonts to be changed, say in Excel (optionally), and save it as CSV-file which will be used by the script. But so far you have to make minor edits to the script:

At the very beginning you'll see the first variable which is the array of arrays containing the names of the fonts in the format

[ "Find this", "Change to this" ],

Here I used the fonts installed with InDesign to make sure that everybody have them and can test the script using my sample.

The left element is 'Find this', the right one is 'Change to'.

The family name and font style should be separated by a tab: either \t or by actual tab (by hitting tab on the keyboard)

The find-change pairs (the elements of array) are separated by commas so make sure that you won't leave a comma after the last element (see the screenshot above).

Then you can select the script in the Batch processor like so:

The 'change fonts' script does the following:

1. changes the fonts in all the paragraph styles
2. changes the fonts in all the character styles
3. changes the fonts applied as a local formatting in the same way as the 'find this font and change to that font' feature works in the Find-Change Text dialog box. Note: to illustrate this point, the first paragraph in my sample is set to Letter Gothic Std  and Minion Pro - Bold, Italic and Bold Italic.

The script changes Minion Pro - Bold, Italic and Bold Italic to Myriad Pro (Letter Gothic Std obviously is left unchanged).

Before

After

Here's the script:

var fontList = [
    ["Minion Pro\tRegular", "Myriad Pro\tRegular"],
    ["Minion Pro\tBold", "Myriad Pro\tBold"],
    ["Minion Pro\tItalic", "Myriad Pro\tItalic"],
    ["Minion Pro\tBold Italic", "Myriad Pro\tBold Italic"]
];
    
main();
function main() {
    try { // if something goes wrong in the try-catch block, the batch processor won't stop here. It will log the error message and continue further
        
        var newFont, paragraphStyle, characterStyle,
        doc = app.activeDocument, // The frontmost document
        paragraphStyles = doc.allParagraphStyles,
        characterStyles = doc.allCharacterStyles;
        
        // Change in paragraph styles
        for (var p = 1; p < paragraphStyles.length; p++) {
            paragraphStyle = paragraphStyles
;
            newFont = getNewFont(paragraphStyle.appliedFont.name);
            if (newFont != null) {
                paragraphStyle.appliedFont = newFont;
            }
        }
        // Change in character styles
        for (var c = 1; c < characterStyles.length; c++) {
            characterStyle = characterStyles;
            newFont = getNewFont(characterStyles.appliedFont + "\t" + characterStyles.fontStyle);
            if (newFont != null) {
                characterStyles.appliedFont = newFont;
            }
        }
        
        for (var i = 0; i < fontList.length; i++) {
            var changed;
            app.findTextPreferences = app.changeTextPreferences = NothingEnum.NOTHING;
            app.findTextPreferences.appliedFont = fontList[0];
            app.changeTextPreferences.appliedFont = fontList[1];
            changed = doc.changeText();
            app.findTextPreferences = app.changeTextPreferences = NothingEnum.NOTHING;
        }
    }
    catch(err) { // if an error occurs, catch it and write the  document's name, error message and line# where it happened into the log
        gErrorLog.push(doc.name + " - " + err.message + ", line: " + err.line);
    }
}
function getNewFont(oldFontName) {
    var newFont = null;
    
    for (var p = 0; p < fontList.length; p++) {
        if (oldFontName == fontList
[0]) {
            newFont = app.fonts.itemByName(fontList
[1]);
            if (!newFont.isValid) {
                newFont = null;
            }
            break;
        }
    }
    return newFont;
}

Hope this helps.

— Kasyan

For InDesign documents you can use Type>Find Font... (not Find/Change) which lets you change a document's fonts with the option of updating any styles that use the font with one click. It is certainly scriptable and one likely exists, so ask in the scripting forums.

I hope you work with a logical build up Paragraph and Character styles with the very same name in every document. Import these styles from a clean source document and overwrite the existing styles. Otherwise, you have to do the hard work, document by document with find and replace font, and replace them.

I've moved this thread from the (fairly quiet) Type & Typography​ since this isn't really a question about type, but more of a question about how to use Adobe software. Thus it is now in a product-specific support forum. I would recommend you create a post in the Illustrator​ forum as well since the answer is likely to be different for each software.

That being said, perhaps this would be a question for Illustrator Scripting​ or InDesign Scripting​, but I'm not familiar enough with either of them to know for sure.