Our lab does a large amount of pamphlet binding, for music scores and other publications. We order binders with the security strip built in. This alleviates the need for our students to be ever-conscious of remembering to include one, and it saves a bit of time as well. We order binders in multiple sizes, and we use the type with clear covers for music scores.
These are affixed inside pamphlet binders and are used primarily for pamphlet-sized materials which are unsuitable for either stitching or stapling directly into the binders. The most common reason for this unsuitability is fragility, and for these materials a sleeve is also made to facilitate removing the item from and returning it to the envelope without damaging it.
These strips are concealed within books and enclosures as a security measure. They have a peel-off backing of release paper and are self-adhesive.