I'm working on a map graphic, and I'd like to create an effect for sandy shoals, such as you see on this image. By default, I could just have the outline as a heavier dot, and the fill as a tile using smaller dots. But I'd love to be able to mimic the vignette effect that appears on this hand drawn map. Suggestions? Thanks
Option A - A Plug in.
I, personally, would make my life easier and use the Phantasm plug in from AstuteGraphics.com. It's not a free plug in, but for me, it's worth the expense specifically because it does many things in 5 minutes that would otherwise take hours to try and create.
Start with a basic shape that's a gradient mesh.. dark edges, lighter center....
(You can use non-mesh objects as well. But for this example the mesh works better).
Effects > Phantasm > Halftone to bring up the Phantasm window...
What this does is use values to determine the size of halftone dots/characters. The darker the value, the larger the dot.
From there it's merely a matter of adjusting the settings in the window....
You can also adjust the curves in the dialog window to refine the appearance....
I believe there's a free trial available at Astute's site. That may suffice for a single project.
You can leave the effect as "live" to adjust further later, or expand it so it's "baked in" in case you need to adjust manually.
Quite honestly getting gradient meshes correct on irregular shapes will be more difficult that any of the plug in adjusting.
In the past, Astute Graphics has provided me with free software in exchange for my evaluation and opinion.
However, I do not benefit in any way should another user choose to purchase Astute products.
Option 2 - A Blend
Two dotted strokes.. blended...
This provides the decrease in dots, but everything remains rather uniform otherwise. This could be accomplished with blends, but things would probably need sectioning to get the drop off correct. I didn't spend any real time on this blend.. so it leave much to be desired.