nonplastic

The story

1. Proto-Indo-European*né
2. Proto-Germanic*ne
3. Proto-Indo-European*ís?
4. Proto-Indo-European*h₁óynos
5. Proto-Germanic*ainaz
6. Proto-Germanic*nainaz
7. Proto-West Germanic*nain
8. Old Englishnān
9. Middle Englishnon
10. Old Englishnān
11. Old Englishnān-
12. Middle Englishnon-
13. Englishnon-
14. Proto-Hellenic*plátʰyō
15. Proto-Hellenic*plát͏̌t͏̌ō?
16. Ancient Greekπλάσσω (plássō)
17. Ancient Greekπλᾰστῐκός (plăstĭkós)
18. Latinplasticus
19. Englishplastic
20. English todaynonplastic

From non- + plastic.