Since copy-pasting panels and full-black panels were already mentioned, I'd say that 'in-universe' posters, advertisements, and documents. There are not bad themselves, but few years ago, a few books were using them to blatantly inflate page counts.
Nowhere Men was probably the worst offender. Whenever there was a transition between different locations, you could expect a full or two page splash like this. This shit just jarring. At it usually happened at least twice an issue, so it's usually at least 2 to 4 pages (~10 - 20% of the floppy) being wasted.
Unless these things tell readers something important to the main plot, it belongs at the end of an issue if you want to make it a full-page. If you want to use it to 'establish the mood,' just use it in the panels. Shit like that would make backgrounds more varied.
>>1012835
That's rookie shit. Solid black double splash page with one word balloon is how you do it. Eisner Award nominated book, everyone.