This video demonstrates how to prepare the vest base for the YES Unit: Engineering Safety Vests, Lesson 5
Use a pair of scissors to cut a file folder in half along the center crease.
Using a single hole punch, punch 2 holes on one of the folders approximately 8" apart and 1" from the longer edge. Repeat this process on the other half of the folder.
Loop one piece of 18" string through one of the holes on both folders and tie together to make shoulder straps. Repeat this process with your other piece of string on the opposite side of the folder.
Loop the strings over your shoulders so one piece of the folder rests on your back and the other rests on your front. While wearing the vest prototype base, shorten or lengthen the strings to adjust its how it sits on your body.