Is it safe to underpower an EL wire driver/inverter?

I'm working on a wearable EL wire project and playing around with a few things. I have a small 12v inverter(linky); is it safe to power it with, say, 6 volts?

The reason I'm considering this is that I'd like to have two brightness settings, one for the day, the other at night. I thought I'd try switching between using 6v and 12v to see if that would have the desired effect. Is that reasonable? Is there something I could do that would work better?

It all depends on the specific inverter you have - certainly some are made to be dimmable.

You might have a look here:

Thanks Nigel, you rock. I didn't think to search for "dimmer" which in retrospect was dumb. It looks like it's a simple PWM dimmer; the site says it's usable with any "adaptable" driver which as far as I can tell is most of their drivers.