Grades K–2 · Everyday Life
How can one string close a whole bag?
A drawstring bag can change from a wide opening to a little bunch. A cord runs through a tunnel of cloth around the top. The cord can slide inside that tunnel.
Pulling more cord outside the tunnel leaves less cord around the opening. The cloth has not become smaller. It gathers into folds along the shorter loop, bringing the sides of the opening closer together.
Follow the orange cord through the blue cloth tunnel. The lower view shows folds, not cloth disappearing.
A knot or a cord lock can help keep the string from sliding back. When the cord is loosened, the folds can spread out again and the opening grows wider.
The same cloth can make a wide mouth or a narrow one because its shape can change. A drawstring turns a pull at one place into a change all around the bag.
About this explanation
This shows a simple single-cord bag; double-cord and locking designs route their cords differently.
Starting knowledge: Notice that soft cloth can fold and that a string can slide through a loop.
Sources
- Yarnspirations / Coats & Clark — Drawstring Organizer sewing pattern