These only use about 1.2g of filament, so don't be shy, print several at a time. They are only 0.8mm thick and print in just a few minutes, depending on if you have ironing turned on or not.
The original file is 30mm wide by 50mm tall - scale in your slicer to your heart's content. The label area is 30mm by 17mm which is more than enough for writing with a permanent marker or the common ½" tall labels as shown in the photos.