Glen Check
While tartans are arguably the most familiar checks to most individuals, Glen check is likely the most common for suits.
This check, often called Prince of Wales check, resembles a tartan, though it is primarily monochromatic. It utilizes bands of vertical and horizontal stripes which, when viewed as a unit, create a wider check effect in the fabric.
Glen check has deep associations with the country and weekend wear – having been created for use by English nobles in Scotland who lacked a family tartan – though it is appropriate for most semi-formal occasions. It may be frowned upon in certain professions with a particularly strict dress code but should be acceptable if not welcome divergence for most men & women.