Matte Paintings
 

So I've noticed that this show sometimes paints in details, entire backgrounds and sometimes (these are the most obvious ones) characters rather than render them in CGI like most other things. The reason is obvious, creating assets in CGI is the most expensive part of TV cartoon and thus this needs to be done in order to prevent the budget from being drained on stuff that isn't likely to be reused.

However, after rewatching season 2 on DVD, I realised that it happens a lot more than I used to think when watching the inferior quality online streams. How many have you noticed?

Can't say I ever really noticed, but probably largely because I just expected it. In terms of time management for model creation and render time (not to mention this is happening on computers and it would just create larger and larger file sizes, slowing it's functioning and rendering) it's not really that feasible to go too overboard with trying to model everything out to a great distance or the far horizon/skyline. Or anything that's not going to be close up. Granted they would not have to do it all in great detail if it's tiny distant objects, but it's still adding unnecessary workload that could be solved in a more traditional way.

It's very noticeable when they walk into the bar at the start of journey into Mikey's mind.

But I can't say that it bothers me in any way. After all, it's background stuff and it stays in the background.

I've noticed quite a few. It's most obvious in New York (i.e. the skyline) and in any outdoor background scene.

It's glaring when you pay attention to detail. The show really needs a budget increase.

I notice it, but it doesn't bother me at all. Even though I know it's a budget thing, it just looks like a stylistic choice to me, and it's just as beautiful as the CG stuff, in my opinion.

So not even at the star of season 4 when some of the aliens were rendered that way?

The only time I ever noticed it was in the Metalhead episode when April and Don/Metalhead were waiting on the roof

I noticed but it doesn't bother me. Like Nasubionna said, just kinda comes off as part of the show's visual aesthetic. I'll admit that the season 4 opener had some stiff glimpses as a result, but it worked just fine.

I do love a painted background!