This fun activity works on tripod grasp. Using a small stamp requires the child to use his fingers in a similar way of grasping a writing tool.
Ask the child to hold the stamp with his/her thumb, index finger, and middle finger.
You may want to set the stamp pad on the opposite side to the hand holding the stamp so that it encourages the child to reach over his/her midline.
To promote the development of visual motor skills have the child stamp between two vertical lines, horizontal lines, or around a circle.
To encourage wrist extension and stabilization place the stamping paper on an inclined surface.