Nov 22 2009
Short answer: usually some combination of…
- Script of the first issue.
- Synopsis of the larger work (either the first issue, arc or series as a whole).
- Sample pages inked, colored and lettered.
For a more detailed look at these three items, I’ll focus on Dark Horse specifically because I think DH is pretty standard. But always check the publisher’s submissions page. For example, Dark Horse’s submissions page is here and Image’s is here.