A woven wrap is a long length of material with a loose weave, this enables the fabric to keep it's strength and shape while having a good amount of 'give' along the bias (diagonal). These qualities make the fabric ideal for carrying a baby, allowing mama and bubbah hours of comfortable walking/playing/shopping :-D
... sleeping...
The downside of this loose weave is that individual threads can become snagged on clothing, car doors, velcro... and be pulled out of the weave, causing a nasty little loop to form on the surface of the fabric. In the most extreme incidences these threads can snap ad become broken, or can even form a hole :-( A broken thread is, unfortunately a hole waiting to happen. Once a hole forms in fabric it's much more liable to a tear... so for many people a broken thread is the death if a wrap... because they can't trust a 'hole waiting to happen' to carry their baby... fair enough! ... but they can be fixed :-) fixed broken threads are not always pretty, but they are safe if done correctly :-)