I'm trying to duplicate the sponging type effect of the background gold part of the following image:
Does anyone know of a tool I can use within Photoshop, or how else I could do this?
As with most things in Photoshop, there are several ways to do this. Here's one:
Step 1: Create a new, oversized document. For this web banner example, a 4 inch x 6 inch, 300 dpi is about right, but you can go bigger.
Step 2: Press D to set your colors to defaults, and choose Filter > Render > Clouds. You're looking for a "pattern" that's about the right size and frequency for your application, so if it doesn't look anywhere close, press Ctrl-F (Cmd-F) to run the filter again until you see something you like.
Here's what I ended up with:
Step 3: This is too fuzzy for our purposes, so we need to greatly increase the contrast. The best tools for this are Levels and Curves. I used Levels:
Step 4: So far, so good, but black and white isn't quite what we're looking for. The entire layer is opaque, which makes changing the blacks to something else a bit of a challenge. Once again, Photoshop has several ways to get there. I'll choose one that gives lots of flexibility later. The first step is to merge the Levels adjustment layer and our clouds layer. Press Ctl/Cmd-E.
Step 5: In the Channels panel, Ctl/Cmd-click on one of the channels to load its luminosity as a selection.
Step 6: Press Delete (Mac) or Backspace (Windows) to remove all the white, then Ctl-Cmd-D to deselect.
Step 8: Now we need to recolor our black clouds. Once again, there are several ways to do this. The most flexible is with a Layer Effect. Color Overlay will give you the look you want, and if you're feeling mischievous, throw in Bevel and Emboss. (Why? -- Because you can.)
I would suggest you to use grunge brush instead of making it by your self it will consume time. you can get such brush here :
and there are several way of doing so, alan already mentioned how to do this so do follow the same if you have good time in your hand else download such brush and complete your work fast.....