Having said that, if the artwork is small enough, I can make an exception, i.e. ACEO and anything up to 8x10" outside measurements, or thereabouts. You can see how I package them in the example here. Another layer of packing fits over the bubble wrap before the box is sealed.
I usually don't ship any artwork larger than this with glass. However, these small sizes, securely wrapped and padded have arrived safely. Take them out of the box and hang on the wall. Instant gratification!