This image is of a Westcott AS-2A leading/type gauge for printed copy.

Leading Gauge: This is the leading gauge I am using in this demonstration. It is a Westcott AS-2A #writingcommunity #publishingtools #booksky #leadinggauge #westcott

Using a leading gauge to find the spacing between the lines of copy. In this case the leading is 13 points.

Leading Gauge: The gauge is transparent. you line up the lines with the bottom edge of your block of copy. All the lines should match. In this gauge the leading is 13 points. You can use the gauge on any printed book. #writingcommunity #leadinggauge #booksky #bookformatting