Adjective
Alkaline or neutral; not acidic.
an acid-free soil
Without using acid.
an acid-free etching technique
Bristol board and even heavier acid-free boards, frequently with smooth finishes, are used for drawing fine detail and do not distort when wet media (ink, washes) are applied. Source: Internet
Wrap them in acid-free tissue paper, not regular tissue paper. Source: Internet
High-quality inkjet prints on acid-free paper can last as long as typewritten or handwritten documents on the same paper. Source: Internet
Books printed between 1850 and 1950 are primarily at risk; more recent books are often printed on acid-free or alkaline paper. Source: Internet
Mimeographed copies have moderate durability when acid-free paper is used. Source: Internet
The propellant is non-polluting: acid-free, solid particulates-free, and lead-free. Source: Internet