I worked on the graphics for 'Facelessirony' lifestyle clothing wear for my friends Scott Bentley and Shadrick Ferrer. If your into dark humor for lighthearted people, skateboarding, bmxing, fashion ,girls/guys with tattoos. Help us out with the kickstarter fundraising.
I figured this out by trail and error with just the mind set of "I know Blender could do this."
Have a scene set up composed and lighted before you just through these nodes on any old Blender scene.These things have to be in place for you to really pull off a painted look the doesn't look like you still have that plastic CG real look.
Blah Blah Blah here is the node setup.
Pretty simple:) Notice the 3 texture nodes. 'Cloud noise' 'Noise' (animated noise) 'Paper'(A grunge texture from the net) I made those on a mesh in a layer that is turned off, so I can go to it and tweak the proprieties without affecting this ones I want rendered.Now you could probably do this in the compositor, but I wanted to keep things simple in there. Here is what the proprieties of each texture looks like.
Basically the combination of the noise,grunge paper texture and displacing nodes abstracts the image.Does it so well that when you use' Boarder' SHIFT + B KEY(No crop checked) the edges take on a arty look like ripped paper on the edges.
You can dial the texture size down(SIZE: 0.010 on cloud noise seem to be a sweet spot) low to where the image become noisy,play with brightness,contrast,and saturation.It will all affect the image. I used blender internal render for this, so you might have a little bit of difference if you use this with 'cycles' but shouldn't be much tweaking.
Update date on cycles:
whom a user a CGtalk used this on a cycles render and it works just fine :)