Alvin - Archival Protective Sleeves - 5 Pack - 18 x 24 Inch - Alvin Archival Protective Sleeves are archival quality, acid-free polypropylene material with acid-free black paper inserts. Alvin Archival Protective Sleeves have universal holes allowing for use in all presentation cases. RF11 also fits standard 3-ring binders. Holes located along long edge. Alvin is one of the primary sources for drafting supplies and drawing equipment in the country. Creative Coldsnow is a pround retailer of Alvin graphic arts, drafting and fine arts products.