Once you have your binding covers picked out, use these binding spines to keep your documents & presentations neatly bound. Durable construction ensures that your finished document is both fully functional & long-lasting. Permanent spines allow your pages to lie flat to keep them manageable & easy-to-read. Sturdy plastic material will not scratch, peel, chip or discolor for lasting durability. 9/16" spine binds up to 105 letter-size sheets. 19-hole binding spines are designed for any comb-style binding machine (sold separately).