heres a little tip to make it more realistic. ehn you have your render in, select the bottom area of it, and blend it / fade it in to ur sig so it looks like its coming out of the sig not just taller than it. the when the bottom is blended in to the sig, click the render layer (or layers) and then press ctrl+t ( or on a mac, mac+t) and then when the box is around the render, right click the pic and then from the drop-down menu that comes up, select "perspective" then slant the image either away or towards the screen for a more realistic look.