Do not use paper thinner than 28 lb. Significantly thinner paper is somewhat transparent, and marks from one side of the ballot show through the paper and interfere with scanning of the opposite side.
USB Drive Recommendations and Compatibility
While our system does not require a particular type of USB drive, some USB drives will not work because of how they are formatted.
There are a handful of USB drive models that we have tested and recommend to customers. We selected them because they work with our system, have reputable manufacturers, and can be bought at a reasonable price. You don't need more than 8GB in size, but for most of our recommended models the minimum you can buy is 16GB.