A seam ripper is a tool used in sewing that quickly undoes stitching. A seam ripper is also used to make buttonholes and cut threads.
A typical seam ripper consists of a handle attached to a U-shaped blade. The blade is longer on the bottom with a protective ball on the top point. The cutting edge is on the inner curve of the blade.
To use a seam ripper, the user places the pointed end under the thread and moves it up the seam that is to be removed. A buttonhole is made by piercing the fabric with the pointed end and then cutting the hole with the blade.