imperforate (adjective)

1. The imperforate façade of the modernist building gives it a distinct and minimalist look.

2. Why did the envelope go to therapy? Because it couldn't stand being imperforate anymore!

3. He wrote her a love letter on a sheet of imperforate paper, symbolizing their unbreakable bond.

4. In the comic strip, the imperforate wall creates a secret hiding spot for the protagonist.