What gauge wire should I use for ranunculus? I have started some, and I think they are too heavy for the wire I got. I would like to make them about 3 inches wide. Also, should I lightly dust them as I go, or wait until they are done? Any help would be appreciated.

I'd use a pretty heavy wire, if you're talking about wiring the center.If the petals are going to be wired too it can be a lighter gauge, but to support the whole thing it should be sturdy.

You can do those unwired, too, but I assume you need them on wires?

I'd be inclined to dust as you go due to the tightly wrapped nature of the petals. Then I'd over-dust the entire blossom to complete the look. Otherwise I think it would be extremely difficult to get to the interior of the blossom.
I've yet to make a ranunculus, but that is how I'd do it. Also, I make the base gumpaste a slightly lighter color than the finished flower and use dusts to darken or highlight.

Jan