Acceptance criteria for materials is no easier to do well than it is for machines (see last blog post). Obviously, you want to specify certain web chemistries and certain wound-roll geometries such as length, width and thickness. Still, that may not be nearly enough to cover some common issues.
Here we will confine ourselves to web-handling issues. One large complaint area is wound-roll defects. Another large complaint area is baggy webs. The good news is that we might be able to "kill two birds with one stone," so to speak. That is because most baggy webs are not made baggy but rather are made with an uneven caliper (basis weight, density, gauge, thickness, etc.) profile variation across the width. These uneven thicknesses stretch the web more (permanently) over the gauge bands than elsewhere.
Yes, winding looser can help, but that misses the point here. That is that profile variation and bagginess are intimately connected. Guess what? Many wound-roll defects are also either made or made worse by thickness profile variation. Measure and manage profile variation, and you reduce almost all bagginess and many winding defects.