Mattel’s new “beautronics” device aimed at tween girls, the Barbie Nail Printer, is a glorified inkjet printer that customizes and prints designs on your fingernails. Neat idea in theory, though a bit pricey at $180. However, Mattel has apparently overlooked an essential part of the inkjet printer business model: selling new and overpriced cartridges. The problem, reader Richard writes, is that the company refuses to take orders for new cartridges, saying that they won’t be available until next year. But I want pink leopard print fingernails now!