I hand paint most of my enclosures with acrylic paint pens. The paint is fragile until baked but even then I like to have more protection. I like to user pour on epoxy resin, the same stuff used for countertops, to protect the artwork on my pedals. This is a video goes through my process from beginning to end applying epoxy and finishing a couple pedals.
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If you like the plastic tub and want to buy Tyrkisk Peber, these are the ones I buy: https://amzn.to/31R0Wx2 but they are a little on the expensive side. I really like them so I get a containers every 4 to 6 months.
I hope you enjoy.