How To Do A Metal Studded Dot Pattern For Signatures?

So I was reading some Grunge Signature tutorials over on another site and on one of the tutorials this was the finished product:

http://i15.photobucket.com/albums/a3...photosho-1.jpg

But the guy left out how to do the indented/studded metal looking pattern that he layed over the top of the signature. I tried contacting him about it and he hasn't gotten back to me yet.

So how exactly would I do this? I searched all over the place for how to do different techniques for "patterns", but wasn't able to find anything other than how to make standard patterns such as dots, scan lines, etc. I can't seem to find anywhere that explains how to do more advanced patterns like the one shown above. I'm not even sure if "patterns" is the proper GFX term for it though, I was just searching around on Google in hopes of finding out what the name is for those designs that people put over the top layer of their signature and came across "patterns" which seemed to fit what I had been seeing. Because I've seen several people with that type of thing on the very top layer of their signature, most of the time it's scan lines over a grunge type signature.

Any help would be great, I hope I'm making some sense...it's really difficult to explain what I'm asking for when I'm not even sure if I know the proper term for it.

-Thanks