This is our tried and trusted photoshop trick to making our graphics look perfectly aged, and retro, and grainy. The Free Grit Texture Photoshop Action is based on the Youtube video we made (watch here) which our pal, Doc Reed, kindly took and made into a photoshop action!
We use this action to add a subtle retro feel to instagram, dribble, and twitter posts. But it also works great for any artwork around 1200px to 1600px. It adds tooth to the crisp lines, then softens the edges (much like the effect you’d get if something were screen printed), and finally adds noise and grain for a subtle, yet effective, end result.