Slightly Off Center

Thought I'd get a head start on my next production run last week: threw forty mugs for a Great Harvest restock order. Come evening, when they were the perfect consistency to impress their logo... I couldn't find the stamp. It wasn't on the table (where it should be), wasn't in the box of stamps and sprigs (where I might conceivably put it for safe-keeping). I even dug out the boxes and detritus behind the table, in case it'd fallen over the edge. No luck.

These are not my standard mug shape, so I couldn't just handle them and put them in the booth. All I could do is double wrap them in plastic, put them on the lowest shelves, and hope they keep until the replacement stamp comes from rubberstamps.net.