This is the 6505th most frequent Catalan word.
plàstiques
"Plàstiques" in Catalan refers to "arts" or "plastic arts," specifically artistic disciplines such as painting, sculpture, and design.
In this sentence, 'plàstiques' is used as an adjective referring to 'bosses', describing the material ('plastic') of the bags.
Les bosses plàstiques són un problema mediambiental.
Plastic bags are an environmental problem.
Here 'plàstiques' is used metaphorically in 'arts plàstiques' to describe arts that involve physical creation and manipulation of materials.
Les arts plàstiques inclouen pintura i escultura.
Visual arts include painting and sculpture.
In this context, 'plàstiques' as part of 'tècniques plàstiques' describes techniques related to shaping or forming materials, specific to artistic practices.