Which Outdoor Sealer Would You Recommend?

HI all - I used Rust-oleum Metallic Finish in Copper to spray paint a bunch of ceramic planters I have, and keep outdoors on our covered patio. The paint held up well all Summer last year, but over the Winter, there is now wear and tear to the finish - which is to be expected.

I'm going to use this same spray paint again now to recoat the planters with a fresh coat of paint, but I'd also like to apply a sealer/topcoat to help the paint hold up longer.

I've been considering using the Rust-oleum Triple Thick Glaze for this, but I am wondering if that is the best product to use in this application, or is there something else I should consider.

These planters will be kept outdoors on a covered patio, so they won't see much rain (if any).

Thank you for your advice!

JayDee