Our classic welded polypropylene sheet protectors have become the industry standard for high quality presentation and presentation of artwork and documents. The weld parallel to the binding edge acts as a hinge, allowing the sheets to lie perfectly flat, making these sheets ideal for use in screwpost books. Available in 10 standard formats, these sheet protectors are compatible with all major brands of portfolios including those by Prat, Anglers Roslyn and Martin Weber. These sheet protectors feature superior scratch resistance to make your work look better longer, a non-stick finish to prevent adhesion to your artwork and a thick liner sheet to support thin or fragile artwork. All formats are top loading. Made of inert, unplasticized, heat resistant and chemically stable archival quality, heavy-duty .0045 polypropylene. Lined with 10 pt. black acid-free and lignin-free paper. Both plastic and paper pass the Photographic Activity Test (PAT) and meet all ANSI requirements for archival storage. Packed in tens in a protective, resealable bag.