I think it is a creative idea to challenge yourself with that. Even though people use brushes, etc. because they are sick of the filters and whatnot, it's nice to try a different approach every once in awhile.

I like how the black lines add some depth to the sig. I'm not a big fan of the blue horizontal stripes, maybe try different designs/textures? Overall, it looks nice for default photoshop options. Keep working on it.