A few tricks to teach you how to distinguish acid-free document boxes from kraft document boxes.
The acid-free paper file box looks similar to the kraft paper file box at first glance. Those who are not in the industry or who often do it can’t tell the difference. In the end, some unscrupulous merchants may fool them and buy cheap goods at high prices. Today, the editor will tell you how to identify acid-free document boxes and kraft document boxes.
The first point is to distinguish from the paper:
Acid-free paper file box: Double-laminated with 340g acid-free paper.
Kraft paper file box: general carton cardboard, about 250 grams (not kraft paper in the strict sense)
The second point is to distinguish from the thickness:
Acid-free paper file box: 680 grams of acid-free paper after double lamination, the thickness of the paper is one millimeter
Kraft paper file box: about 250 grams of boxboard, about 0.7 mm after double lamination
The third point is to distinguish from the color and flatness:
Acid-free paper file box: uniform color, light color, smooth surface of the paper
Kraft paper file box: uneven color, large color difference, rough surface