|I love patterns, and recently have discovered that I had duplicates of the same pattern.
To help me avoid this, I've started my own personal pattern catalog. If I buy a new pattern, I will print out a copy of the visual, then I will place it in a 3 ring binder that has been divided by pattern company (as well as have it in numerical order). On the opposite side of the paper I will print off the pattern info -such as yardage required, notions, etc.,
It especially helps me as I can bring this with me whilst perusing pattern sales, and I can automatically check if I have the pattern or not, thus helping me avoid any duplicates.
Even older OOP patterns are easy to include in my catalog, I simply use my all in one printer, and will copy the pattern envelope front and back.
As I purge my patterns, it's as simple as removing the paper.