Why is my paint texture showing on these tiny resin models?

On parts that small, sanding is the wrong tool almost every time. What actualy works is building up a filling primer in thin layers instead of trying to knock the layer lines down mechanically. I use a leveling primer thinned down and sprayed in several light passes, letting each one dry before the next. The primer fills the low spots between the layers while the raised detail stays proud, so the lines disappear but your edges and panel lines stay crisp. One or two heavy wet coats will flood your detail, so patience with the thin passes is what saves you. For the really fiddly stuff like bolt heads and internal linkages, the trick is to stop trying to make those surfaces perfect at all. At that scale, a couple of thin primer passes plus your color coat is ussually enough that the texture reads as cast metal or part of the part itself. Nobody can see individual layer steps under paint at that size unless they're catching light. If a specific spot bothers you, a light burnish with one of those flexible sanding sticks on just that area, not the whole piece, removes the catch without eating the detail. Paint choice matters too. Thin your color down more than you'd think and airbrush it if you can. Thicker brush-on paint sits on top of the texture and magnifies it, while thin coats settle into the primer surface. A gloss or semi-gloss color also hides layer lines way better than anything matte, since matte scatters light across every tiny step.

Also worth saying: some of this is fixable before painting. Printing at a finer layer height and dialing in your exposure so layers fuse cleanly makes the texture shallower to begin with, which means less primer work later. Reorienting parts so the layers stack along a less visible face helps on the flat panels too. For the sheer volume of little panels, do your primer and base color as a batch before you ever seperate anything. Paint everything while it's still on a common sprue or sticking strip, handle by the waste tab, and only cut pieces free once the color is down. That turned a week of misery into two evenings for me.

Seconding the batch approach, that was the game changer for me on a small model build last year. I stuck all the tiny bits to a strip of masking tape on a paint stick, sprayed the primer and base coat in one go, then flipped and did the other side. Only thing I'd add is to put a toothpick of wood glue between the part and the tape for anything with a hidden underside, because the tape sometimes pulls paint off where you don't want it.

Ha, this takes me back. Before resin we fought the same battle on white metal and pewter kits, and the old fix was a wipe-on leveling coat, just gloss varnish cut way down with thinner, brushed on sloppy and left to settle flat. Same idea as those thin primer passes but you can work it into bolt pockets with a brush tip. One other trick from the old days that still holds up: check the piece under a single raking light before you commit to color. Desk lamp low and off to the side shows every catch your fingertip misses. Under the bench fluorescents everythign looks fine, then sunlight hits it and ruins your week.

I tried the leveling primer idea and doing it in thin passes, and that helped smooth out the visible layer lines. It made a big difference. But I'm still having trouble with some of the tiny recessed areas looking a little flat. How do I make sure the edges around those little chassis bolts get that same solid color coverage without running into the texture problem again?