Some people like unique tattoos. Ruler is a unique tattoo material. The meaning of ruler tattoo is integrity. Ruler is a tool for drawing line segments (especially straight ones) and measuring length. There is usually a scale on the ruler to measure the length.
Some rulers have special shapes in the middle, such as letters or circular holes, which are convenient for users to draw pictures. They are usually used to measure and calculate the length. They are generally divided into tape measure, vernier caliper, right angle ruler and ruler.