Great idea! We have a similar system at NYPL that we all really love -- we keep a three-ring binder with paper samples in polyester sleeves meant for business cards and a source list that tracks as much information as we can get from the vendor on the fiber, production style, size of original sheet/roll, thickness, gsm, and pH for each sample.

The "Paper Sample Book" originated with my predecessors and has been in use in the lab for many years. The "Paper Sample Book" joins our "Lab Inventory" and "Recipes" binders as key ways to keep information centralized and handy for the whole lab. We update the sample book every time we get new paper types or replenish stock. It's arranged by fiber type and weight so having them in business cards sizes is useful because you can take them out and compare them against the original or another potential repair paper. The clear sleeves are nice because you can put them on a light table to compare laid lines or fiber distribution when selecting a repair paper.

I'll tweet some pictures!