Elmer’s Liquid School Glue, Washable, 4 Ounces – Link

Amazon has this marked down to $0.50

• Make slime and bond materials like paper, wood, fabric and ceramics
• Safe, washable, and non-toxic
• No-run formula is adjustable before setting
• The #1 teacher brand, it’s ideal for arts, crafts, and school projects
• Smooth, classic white glue formula is perfect for making slime at home or in the classroom!