Quick Siggy Question

[stephc777]

So I created my first ever signature for the INSD celebration. I love the way it turned out, but it is not centered in the middle of the bottom of my posts like everyone else's appears to be. (I did do a little searching in the forums before posting this question, but didn't see anything addressing this LOL) Is there an extra step I need to take or a width the original file needs to be in order for it to be centered properly? TIA!