Desk Ruler

• Desk rulers are flat, usually 12 inches long and made of materials such as metal, plastic or wood. You can use it to draw straight lines, measure distances and use as a guide for cutting. Standard rulers usually have a scale in both inches and centimeters.
  
  

Folding Ruler

• Folding rulers either fold or retract to save space when not in use. Examples include carpenter's rulers and tape measures. The rulers can reach distances farther than 15 feet. A carpenter's ruler is composed of several small flat rulers whose ends are connected together to form a large ruler when unfolded. Carpenter's rulers use scales accurate to 1/16 inch, for exact measurements.
  
  

Line Gauge

• A line gauge is a specialized type of ruler designed for use with paper and printing. There are usually four scales available: points, metric, inches and picas. Two are on the front and two are on the back. Line gauges are made from stainless steel. The length of the rulers can range from 6 to 24 inches.
  
  

Fabric Tape Measure

• Fabric tape measures are made of flexible but sturdy materials such as fiberglass. You can fold a fabric tape measure around almost any object. They can be used for measurements on the human body to fit clothing exactly. Fabric tape measures have scales in inches and feet. Sometimes they have millimeters and centimeters on the back side of the ruler.