I received the replacement tinder the other day from UST (thanks!); these batches were in small cardboard boxes, same gray foil wrapper. Just need to get outside and give them a try...

Discovered by accident that Lock & Lock makes a small round plastic container that is 100 ml / 3 oz. / 0.11 qt. in size and holds five pieces of WetFire tinder perfectly. Both Uwajimaya and H Mart (asian food stores) carry lots of various Lock & Lock containers. Should work well for protecting the tinder if anyone needs something cheaper than an Otterbox or Pelican case.