Required materials: scissors, art knife, empty beverage bottle.

1. Remove the outer wrapping paper of the beverage bottle, and then cut it at 1/3 with a utility knife.

2. Trim the incision of the beverage bottle with a utility knife and scissors to prevent burrs from pricking your hands during use, and then trim it neatly.

3. Starting from the incision, cut the bottle body into vertical strips with scissors, with a width of 6 mm and a length of about 4 cm.

4. Press the cut plastic strip horizontally to make it perpendicular to the beverage bottle.

5. Select a vertical bar and fold it to the left. The top of the vertical bar faces the edge of the third vertical bar from the left.

6. Continue to fold the vertical bars cut in step 5 in turn until all the vertical bars are folded.

7. When everything is finished, put the pen in and you can start using it.