Many years ago, when a fashion fabric store was going out of business, I bought several pattern file cabinets for $25 ea. One is now dedicated to my LA with thread in 1 drawer, pantos in 2 drawers, tools in 1 drawer and templates in another.
The pantos are displayed in a binder with sections for the types: general, jeuvenile, floral, leafs, holidays.... On the divider page there is a very small picture of design of each panto in that section. In the section there is a full size on standard size paper to show the density and on the back a picture at about 50% to show the design. This page also includes the name of the design and other important information. They are each rolled and have a rubberband (although I do like the paper towel tube idea to protect the pattern-it's a big $investment), with the name on the outside. The file drawer is divided into sections corresponding to the binder. The customer can easily flip through the binder.