: If you have a 3D printer, you can download free "screamer" whistle files from sites like Thingiverse.
: Fold about half an inch of each end of the strip outward to form a "T" or bridge shape. Screamer Free Download
If you want a "screamer" that makes a loud bang rather than a high-pitched whistle, you can follow a Paper Popper tutorial which typically uses a full sheet of A4 or printer paper. Printable Templates and Resources : If you have a 3D printer, you
: Use scissors to cut a small half-inch slit along the center of that fold. Printable Templates and Resources : Use scissors to
: You can find " The Simple Screamer ," a classic guide to papier-mâché, for free streaming on Internet Archive . If you'd like to try a specific style: 15 Second Paper Screamer : 4 Steps - Instructables
: Use a piece of paper about 1 inch wide and 5 inches long (though exact size isn't crucial).