1. Nylon.
2. White sugar.
3. Fine salt.
4. Peppercorn.
5. Ground black pepper.
6. Coffee grounds.
7. Wood.
8. Ballpoint pen.
9. Printed paper.
10. A staple in some paper.
11. A grain of pollen.
12. Pollen caught in fabric.
13. Needle and thread.
14. The edge of a razor blade.
15. A moustache hair.
16. Lots of moustache hairs.
17. The surface of an old copper penny.
18. A fruit fly.
19. More of a fruit fly.
20. A cloth.
21. The surface of a ball bearing.
22. The sticky bit of a post-it note.
23. Cotton.
