/diy/ - Do It Yourself

Sup /wwg/

Just for reference, I consider myself to be a novice+/intermediate woodworker. I've built some shelves and other furniture as well as walls, floors and all that stuff, but I've never touched upon advanced joinery or stuff like that. Anyways

Coming up at work in a few weeks I might be tasked with building a bunch of pic relateds in different sizes, baseline varying between 20 and 50 cm or so. Top and bottom are not necessarily rectangular, they could also be rhombic. They need to stand upright on their own and securely support a moderate weight (I'll probably put a sandbag inside each for that)

I want them to be a clear, even, bright color, giving the illusion that it's all one piece as if it's a plastic cast or something like that. No joints or cracks showing. Earlier when I've filled cracks between particle board with multipurpose filler it always shows, even after sanding furiously and painting several layers over. I'm thinking of going for MDF for these even though I hate working with it. Should I use acrylic filler or something else instead? Or should I just paint it? Any special types of paint? I'm afraid that even if everything lines up perfectly, the stress from lifting them up and moving them will crack the paint between the plates and ruin the aesthetic if I don't use some sort of filler between them. I guess I should glue them? I'm planning on painting, sanding, painting again and sanding a last time, but honestly I know very little about painting or surface treatment in general so I'd appreciate some input