Is there a type of fold for one-sheet flyers where the last thing a reader reaches while working through it in a natural way is a full-page spread, and where sections of that full page spread are not seen before it is reached?
Trying to think about how that could work is giving me a headache... and I'm starting to run out of paper to test-fold :)
The closest I've found so far is (from the book Forms Folds and Sizes) the '6 page barrel fold'. It gives everything except the very back panel before reaching the centrefold, which is close enough, but 1/3 of the centrefold becomes visible in isolation after the first opening.
The problem is that one of the brown centrefold panels is shown on its own at step 2 separated from the others - I'm hoping for a fold where the whole centrefold is introduced as one unit, as late as possible in the reader's progression through the folds. Is this possible?
Taking a classic 'Closed gate' fold (which introduces the centrefold too early)...
...and turning it around would theoretically solve the problem...
...but unfortunately, in some very unscientific testing on colleagues, I find that while about 50-60% read through like that, about 20-25% read it like this...
...and about 20-25% read it like this:
...which would result in content being read out of sequence and the natural flow being broken. How they read these seemed to hinge on how much the leaflet happened to fall open while they turned it over in their hands.
Edit--
The reason why reading order is key is that the content is a series of information panels, which together build up a complete picture, and go progressively deeper into a topic. So, if they are read out of sequence, it might not be obviously wrong to a reader as panels cover separate topics, but it would make less sense because the reader will be trying to understand a detailed topic before they've understood more basic foundational info.
If that's hard to visualise, imagine something like the structure used in The Oatmeal, where a series of points are made that are factually independent, but together progressively flesh out an overall picture. Now imagine you were producing a leaflet version - you don't want to distract from the flow of the content, and you want to be sure it's read in the right order else the message can be weakened or muddied.
And the reason the centrefold needs to be last or nearly last is, that's how the content is - the final point is a difficult multi-faceted point that needs the extra space and needs the prior background to have been already read.