Avery 89105 Customize binder spines with professional-looking spine inserts. Microperforated cardstock allows easy separation of each spine. Firm cardstock makes it easier to insert each spine into a binder. Spine inserts work best with Avery Binders featuring Avery Easy Insert spines. Inserts are compatible with laser and inkjet printers and are easy to format using blank and predesigned Avery Templates.