Bother! After some fiddling around, found it out. Here’s an example of a quick script to change the weight of each character in a selection so that it goes from the lightest weight to the heaviest (the result is the text gets darker and darker the further along you go). Note: you have to already have applied the Acumin Variable Concept font to the selected text, and you also have to select the text itself (it will only do the selected text):

//

if (app.documents.length == 0)
{
alert (“No open documents!”);
exit ();
}
selectedText =app.selection[0].characters;
t=selectedText[0];
myDesignAxesName=t.appliedFont.designAxesName;
myDesignAxesRange=t.appliedFont.designAxesRange;
myDesignAxesValues=t.appliedFont.designAxesValues;
range=myDesignAxesRange[0];
w0=range[0];
w1=range[1];
stepping=(w1-w0)/selectedText.length;
for (s=0; s<selectedText.length; s++)
{
myDesignAxesValues[0]=(w0+stepping*s);
selectedText[s].designAxes=myDesignAxesValues;
}
alert(“Done”);

// End.

It seems now that a lot of this is because laser printers are expecting RGB values and not CMYK values. K=100 means black, but not rich black. (Note also that “output all blacks as rich black” on preferences sometimes has an effect and sometimes doesn’t depending on various things).

Instead, convert to RGB colors when exporting in InDesign.

On the PDF export screen, click the output (on the left hand side) and convert the colors:

Color Conversion: Convert to Destination
Destination: sRGB ICE61966-2
Profile Inclusion Policy: Include Destination

That has done the trick.

Some people have used the “Registration” swatch instead of “Black” for everything black, which sort-of does the trick, but don’t do that. If this is ever sent to a printing press, some pre-press worker will be annoyed, because registration swatch is for registration marks on printing presses.

What I’m after is getting the glyph that is rendered on the screen. The “ff” appears as two characters in the string (which is normally what you get) but the glyph is only one “character”.

This is particularly nasty when one is rendering non-Latin languages, especially fonts with encoding table problems. Some of them are notorious for rendering fine on Apple’s software (such as pages) and coming out totally wrong in InDesign. The solution usually is either to switch fonts (which solves the problem but changes the font of course), or edit the font’s encoding tables with a font editor (which for some languages, is a lot of work). The thing is the glyphs are all there, so if one can dump the glyphs, that would also do the trick (since they’re all unicode).

Sometimes in desperation, one resorts to opening the glyphs screen and clicking the glyphs, but that is time consuming compared to typing at the keyboard.