One of the truisms about programmers is that they prefer not to have to do the same thing twice. That’s why the good ones tend to start keeping code libraries, and the really good ones start doing subtle and elegant things with objects.
Coming from a programming-for-clients background I eventually ended up in graphics (which was what I’d started doing long before anything else), at least partly because when you’re working on something for a client you’re never really finished. You’re always doing the same thing twice. And considerably more often than that as well.
So it is that I don’t particularly like having to do the same design twice, nor do I like sloppy or inelegant solutions to situations.
Some time back I did a design for our local charity race. That design works pretty well on shirts and in smaller scales, but on a poster it’s basically a big field of white without a lot to bring the subjects into prominence. So what I’d done before (last year) was invert the colors in the art, transposing black with white and vice versa.
This is trivial to do in Illustrator, but since I’m using InDesign as my layout tool, the issue I start bumping into is having to keep two different versions of the art around — the standard black-over-white, and the inverted version.
This is not good, for a couple of reasons.
1 If I make changes in one, for whatever reason, they won’t necessarily get reflected in the other.
2. Having more than one copy of a working file is pretty damn sloppy.
Another problem is that InDesign doesn’t easily let you invert colors in placed art, unless it’s a TIFF. (I have no idea why, but it’s apparently been that way forever.) There’s no Invert option in the ink effects choices, and Difference and Exclusion are both inadequate for truly inverting black and white. All you end up with is something black sitting atop something else that’s charcoal grey. Hardly adequate contrast, and definitely not an inversion.
Thus presented with a challenge (remember, I didn’t want to have to invert the colors in Illustrator, though I could have in less than 60 seconds), I started messing about. This is the image I began with. Note that the figures are black on a white field, as originally created in Illustrator.
My little journey of discovery wasn’t as arduous as I’d feared. All I needed to do in the end was create two additional graphics — both InDesign shapes — and place one below the art, the other atop it. To make it obvious what I’ve done, I’ve added some layers to the image, labelled foreground — white, art, and background — black. The art is, as you’d expect, on the art layer.
On the background layer, I created a black rectangle with no ink effects. The art is placed on top of that in its own layer, with its ink effect set to Difference at 100% opacity. That gave me a black-on-charcoal effect, which obviously is not where I want to be. Click the screenshot here to see what I mean.
To rectify this, I placed a white (Paper) filled rectangle above the art, again on its own layer to make it clearer how things are stacked. This, too, is set to Difference ink at 100% opacity. Click the final screenshot here to see the results.
The black and white values in the art are inverted, without my having to alter the source file in any way.
Direct export to PDF works with the final version, as does output to EPS and then distilling. The “inversion” to black is less than perfect — the black is actually a dark grey, though it looks better in a direct PDF export than in something passed through Distiller — but for many uses, I think this is a workable alternative to editing your source art to invert black and white in InDesign CS5.
Spew