The simple genius of the looped tag alone explains why so few bags get lost. On a string-tied tag, according to a spokesperson for Intermec, a tag and printer manufacturer, "the primary stress is applied to a very small section of the tag. With looped tags, force is distributed over the entire width of the tag." Of the few bags that are lost these days, only 3 percent involve "tag-offs," the industry term for a detached tag. It almost never happens. Thank you,oh looped tag.
Of course while tags must remain rigorously attached, they must also be easy for passengers to remove. Intermec's spokesperson raves about the adhesive's "excellent flow properties" — in layman's terms, simply grab the loop from the inside, with two hands, and gently pull apart to remove the tag. A couple of other clever innovations: Like the tags themselves, the adhesive must be all-weather. Early adhesives couldn't cope with extreme cold, so snowy tarmacs would end up littered with detached tags (and lost bags). Also, passengers don't want sticky residue left on their bag's handles — so the adhesive's backing is designed to stay in place on the inside of the loop.
Finally, let's look at what's on the tag itself. In the old days, tags were blank and would be filled in by hand, according to a spokesperson for SITA, an aviation technology group. Later on tags preprinted with the destination were introduced, eventually bearing the three-letter airport codes we know and love today (and some we no longer know — such as IDL, for Idlewild, the previous name for New York's JFK Airport). As airline operations became more complex, elaborate color schemes were designed to help handlers quickly identify where a bag was bound.