Modern Block White Comes in Three Sizes. wood. Our Unique Alternative Wedding Guest Book… Signature Frames. This high quality signature mat is made from a beautiful, highly polished silver-colored alloy. Signed by guests, with our easy to use non-mechanical Signature Engraving Scribe each signature will last forever. The signatures are designed to be very visible, yet subtle so as not to distract from the photo. Once signed your Signature Frame becomes a treasured keepsake.