acid paper

Def: Papel normal que normalmente tiene un grado de acidez alto, lo que contribuye a su deterioro y que generalmente se utiliza como contraposición a [acid-free paper] (papel no ácido)
Ex: However, the consequences of progressive deterioration, both as a result of acid paper and environmental conditions as well as by increased use, are just beginning to be realised.

(n.) = papel ácido
Ex: However, the consequences of progressive deterioration, both as a result of acid paper and environmental conditions as well as by increased use, are just beginning to be realised.