A feather edge is a long, thin tool with one side tapered (the feather edge).
Straight edge
A straight edge is another name for a ruler, and all feather edges have a side which can act as a rule.
Dimensions
There is no universal size for feather edges. However, the following measurements are fairly typical for these tools:
Length (L)
Feather edge length varies depending on the job you are doing. They can usually be found in various increments between 1.2 and 3.0m (47″ and 118″). Which size to use is down to personal preference. However, you may want a longer one to get jobs done quicker or a shorter one for easier transportation.
Width (W)
The width of a feather edge is measured all the way across, not just to the beginning of the taper. They are approximately 10cm (4″) wide.
Depth (D)
A feather edge is around 2.5cm (1″) in depth.
Tips
The feather edge most commonly has a rounded tip but there is a pointed alternative. The rounded tip is useful for gliding over soft materials without digging in, whereas, the pointed tip, or fine edge, is preferred by some people for use in marking out and cutting.
Scale
Feather edges can come with a scale, which allows it to be used for measuring. How the scale is divided can vary, but as an example, some feather edges are marked at 5mm intervals with every 50mm numbered.
End caps
Feather edges are hollow, which makes them lighter and easier to manoeuvre, but this means that the ends are open unless plastic end caps are used. These prevent debris getting inside the tool, which can make it dirty and heavy.