It's important to note that "papel" is a general term and can refer to many different types of paper, such as:
* Papel de carta: Letter paper
* Papel de periódico: Newspaper paper
* Papel de regalo: Wrapping paper
* Papel de lija: Sandpaper
* Papel de construcción: Construction paper
You can also use the phrase "un trozo de papel" which literally means "a piece of paper", but it is less common than just using "papel".