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I read in another topic that pet-g might result in better prints compared to PLA and ABS.

the great thing about ABS though is you can boil some acetone and get a high gloss smooth finish. Is there something similar for petg?

I read about Cyclohexanone, but that seems like it might just be used to glue parts together.

So, Methylene Chloride (Dichloromethane), is a common hobby solvent which will dissolve PETG to some extent. It may not give you the gloss you're looking for.

I would not attempt to boil it, despite working with it frequently in lab grade form, because it has a very fast evaporation rate, potentially leads to lung cancer, and is very thin.

For a smooth gloss finish, I would use Smooth-on's XCT-3D unless you have some particular property of the plastic you need on the surface (Which would probably be compromised by the Di-clo anyways). It's relatively cheap. (~1.01$ per ounce), and has good coverage properties, plus it works on most any plastic.

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