Because I’m “misting” over the object while painting, in a series of very light coats, a lot of the paint and clear-coat gets on the cardboard it’s sitting on and also wafts off in the breeze. Krylon Fusion paint is about $7 a can at Wallmart (USA) and the clear coat was a couple of bucks more.
Home Depot and Lowes have phased out Krylon in favor of Rustoleum and/or their own brand, but reading a lot of reviews convinced me that Krylon Fusion was the best bet. But I don’t plan to do this to any other melodicas until I see how durable the new finish is. I have my doubts about that.