The 25-pack of white GPN45 4 x 5" Glass Plate Enclosures from Print File contains four-flap envelopes used to store and protect glass negatives from dust and scratches. These acid- and lignin-free enclosures are made of a 7-pt. unbuffered white card stock. Each flap has a 1/8" score, so it can close properly and allow room for the thickness of the glass negative.
The envelopes have passed the Photographic Activity Test (PAT), which makes them suitable for long-term storage. Print File recommends storing the enclosures on their sides and not flat to reduce weight and avoid cracks or breakage in the glass. The Glass Plates Enclosures are compatible with Print File Flip-Top Archival Boxes.