cffunction return that is not a string

And just to round out the discussion, in case jyjun didn't catch it, the returnformat that Wolfshade offered is indeed distinct from (and can alter) the returntype attribute which you already have.

There's history behind all this, but the bottom line is that if you are calling a CFC and a remote method via http (not as a web service), then there are these differences in what's returned by default and how that returnformat overrides it.

In fact, you can also control what format you get back in the URL that you send to request such a remote method this way, by adding a &returnformat=plain, for instance (not string, as I first wrote by mistake here).

That ability to override the format via the URL is not covered in the cfdocs page that was offered, since that's based on the CFML Reference, which only discusses the cffunction tag itself. But it is discussed in the CF Developers Guide section on the topic, and also in a blog post from Ray Camden back 10 years ago when all this was initially bubbling to the surface, if you want to better appreciate how it all came about.