For Print: Baseline Grid
We use an 12-column grid with a 6-pixel baseline grid.
Always use traditional type sizes (9, 10, 11, 12, 14, 16, 18, 21, 24, 30, 36, 48, 60, 72) and align type to horizontal baselines to ensure consistent craft in your layouts. The best way to do this is to combine the previously mentioned type sizes with leading in multiples of three (72 font size + 72 leading, 24 size + 27 leading, etc.). See the Typography section for more details.
Your grid should always maintain 12 columns, scaled to the width of your page, with one extra "alley" on each side of your columns.
Space between columns is typically 30pixels/points as a base; if you change your spacing between columns, make sure it is in multiples of 6, so the alleys between rows and columns of content can match.