In Arial, you can find two squares (Unicode 25A0 and 25A1). Choose them and color the first one white; set kerning to -600. Voila! Of course, you can add black stroke to make the shape look as you want.

Use the solid square from Zapf Dingbats (or other square of your choice), set it to white, then apply a black stroke of your desired thickness. No messing about with kerning required!

Those are both clever ideas, thanks.

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Use the solid square [...], set it to white, then apply a black stroke
Sure, nothing easier. I was tired yesterday.

Also you can do that in Webdings... wooohoo

lowercase g, lowercase c -1000

Thanks again to everyone for the suggestions. Now I know how to do it.

Don't use the kerning thing, it's a clunky solution. Simpler is better.

> Don't use the kerning thing, it's a clunky solution

Yep, I appreciate all the suggestions but the single-square one sounds like the best method.

Then, of course, you make it a GREP style so that every time you type a box it automatically gets colored and stroked.

And a two-colour vector image is a dumb solution?

The problem with vector images is that normally in InDesign they don't reflow if the text changes. If you've got an order form with 30 checkboxes as images and the leading changes, you've got to manually go back and reposition each one. A workaround is to paste each image into the text as an inline image, and then it'll reflow, but I've always found inline images to be tricky to work with, so if there's a way to insert a checkbox as regular text it's what I'd prefer to do.

The font Symbojet comes with some combining full-shape glyphs with a zero-width, made to fit exactly to the purpose you describe, in connection to other (frame-like) glyphs.

Thanks Andreas, I'll check it out.

It's always best to do as much as possible natively in InDesign, so Joshua's GREP style suggestion above is a great one.

As long as you use a dingbats font common to Mac and PC there's no reason to start obtaining other fonts specifically for this. Which isn't good news for those selling fonts but your life will be considerably easier.

I'm harping on about this I know, but you don't get any points for choosing more complex solutions, the reader just sees the box.

@JamesM – Well, bugger.