A small collection of some of the many proposals covers I have done.
Proposals (Government/Public - which these are all for) are an interesting design challenge as they typically have strict font size and type requirements, along with specific page sizes and margins. The cover, although typically free range for imagery also has specific content that must be included, some of the cover still have that content while others have had it removed.
The stereotypical proposal client is looking for a cover that looks something like a Steven Colbert Report opening sequence; eagles, flags, explosive patriotism.
Proposals are typically very fast turnaround times, most of these covers were concepted, developed and finalized in less than 15 working hours total, some were on an even tighter deadline and were done in just a couple of hours. That time includes creating backs and spines when necessary as well as prepping for print.
Some of these covers were concepts while others are the actual cover used in the proposal. The sizes vary based on the binder size, more square covers were designed for up to 4" binders.