noun
Refers to the craft material or objects made from it, such as masks, decorations, or props.
文化祭で張りぼての大きな恐竜を作った。
We made a big papier-mâché dinosaur for the school festival.
noun
sham; façade; something superficially impressive
Figurative use: something that appears substantial or genuine but is actually hollow or fake. Often used critically.
His plan is nothing but a sham.
あの会社の好業績は張りぼてだった。
That company's good performance was just a façade.
見せかけ is a more general term for outward appearance or pretense, while 張りぼて specifically implies a hollow, papier-mâché-like sham.
From 張る (はる, 'to stretch') + ぼて (possibly related to ぼてっと, an onomatopoeia for something thick or puffed up). The exact derivation of ぼて is uncertain.