Sneakpeekit Sketch Sheets - 4 up browsers

This skecth sheet is part of a project I've started up two months ago. On sneakpeekit we release for free ready to print PDF A4 sketch sheets for wireframing. They include pixel-perfect grids respecting the most common and modern grid systems (from 320px up to 1140px canvasses), included responsive grid systems. Want to help to spread the word?