Illustrator has some of the photoshoop filters applied as an effect. I you go to the Effect menu and half way down you will see the Effects Gallery one of those effects I believe could. Work either as an effect or as a mask.
This would be another example, just finer texture:
It's an old technique, where sign artists, etc would probably take spray paint and spray the noisy, gradient texture over masked off portions of the canvas/sign. I've been meaning to try this style for some time now - digitally of course.
The style relies on a lot of smart shape-play and nice colors. Your posted example is a great one.
I would also default to Photoshop for such a thing, though. So much easier to just brush on this type of texture to a layer with it's transparency locked. Draw everything in Illy, but then save out a layered PSD for finishing in PS.
OK . . . I am determined to destroy this topic. It's exactly the kind of thing I must know how to do . . .
No disrespect Wade, but . . . your example totally blows, haha. Great thinking, though. I tried it after I saw your post. It almost works . . .
But I'm convinced now that this textural effect is done in Photoshop. Whether or not you want to import the created Photoshop textures into Illy and mask them to vectors, or maybe just Live Trace the texture itself, is beside the point.
What's important here is just how to get this sort of chunky, "binary" gradient.
Back to my Fourth of July poster this morning and I searched for a way to knock my high-detailed spraypaint to something more like the OP's image.
With just a little setup, here's what the Stamp filter did for me:
I'm very pleased with the results. For linear chunky gradients, one could create a tiling pattern to fill shapes with, in Illy. If you know how to use PS and Illy in conjunction this method arms you with the ability to easily achieve the OP's desired result.
Hmm wait a second here folks . . . just hold on!
Wade, I may've spoken too soon. See you really were headed in the right direction. This post officially makes you and I a team! Together, we will conquer JET! ok j/k . . .
Check it, y'all: (this is in Illustrator, BTW)
Took Wade's work and just added Stamp. The available parameters allow you to get it just right. Only thing is that you can't control how large the "chunks" comprising the binary gradient are. So keep you art at the right scale, relative to the Sponge/Stamp texture.
Save it the applied effect as a Graphic Style, or create an action, whatever you wanna do. Your golden.
Hey, I've got the answer !
Actually, once you know the trick it is very simple :
First, you duplicate the object you want to apply shadow on
you apply a fill gradient to your copy correponding to your shadow. The shadow dark will be black and the light part will white with 0% opacity.
Then you apply a the filter mezzotint to this gradient (Effect/pixellate/mezzotint) and you choose the kind of grain you want.
Last, you apply multiply or overlay transparency setting to your grain gradient and lower the opacity to your taste (usually 30/40%).
Finally you put the gradient grain part on the orginal part and you done !
Tip : to make a gradient that perfectly fit your form, use the blend tool between a black line and a withe trsparent line.
I hope this help and ask me if you need more info about that !
I wrote a tutorial about this kind of effect: